Open sourceHEADmane

1 files changed, 6059 insertions, 0 deletions

diff --git a/node_modules/async/dist/async.js b/node_modules/async/dist/async.js
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+(function (global, factory) {
+    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+    typeof define === 'function' && define.amd ? define(['exports'], factory) :
+    (factory((global.async = {})));
+}(this, (function (exports) { 'use strict';
+
+    /**
+     * Creates a continuation function with some arguments already applied.
+     *
+     * Useful as a shorthand when combined with other control flow functions. Any
+     * arguments passed to the returned function are added to the arguments
+     * originally passed to apply.
+     *
+     * @name apply
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {Function} fn - The function you want to eventually apply all
+     * arguments to. Invokes with (arguments...).
+     * @param {...*} arguments... - Any number of arguments to automatically apply
+     * when the continuation is called.
+     * @returns {Function} the partially-applied function
+     * @example
+     *
+     * // using apply
+     * async.parallel([
+     *     async.apply(fs.writeFile, 'testfile1', 'test1'),
+     *     async.apply(fs.writeFile, 'testfile2', 'test2')
+     * ]);
+     *
+     *
+     * // the same process without using apply
+     * async.parallel([
+     *     function(callback) {
+     *         fs.writeFile('testfile1', 'test1', callback);
+     *     },
+     *     function(callback) {
+     *         fs.writeFile('testfile2', 'test2', callback);
+     *     }
+     * ]);
+     *
+     * // It's possible to pass any number of additional arguments when calling the
+     * // continuation:
+     *
+     * node> var fn = async.apply(sys.puts, 'one');
+     * node> fn('two', 'three');
+     * one
+     * two
+     * three
+     */
+    function apply(fn, ...args) {
+        return (...callArgs) => fn(...args,...callArgs);
+    }
+
+    function initialParams (fn) {
+        return function (...args/*, callback*/) {
+            var callback = args.pop();
+            return fn.call(this, args, callback);
+        };
+    }
+
+    /* istanbul ignore file */
+
+    var hasQueueMicrotask = typeof queueMicrotask === 'function' && queueMicrotask;
+    var hasSetImmediate = typeof setImmediate === 'function' && setImmediate;
+    var hasNextTick = typeof process === 'object' && typeof process.nextTick === 'function';
+
+    function fallback(fn) {
+        setTimeout(fn, 0);
+    }
+
+    function wrap(defer) {
+        return (fn, ...args) => defer(() => fn(...args));
+    }
+
+    var _defer;
+
+    if (hasQueueMicrotask) {
+        _defer = queueMicrotask;
+    } else if (hasSetImmediate) {
+        _defer = setImmediate;
+    } else if (hasNextTick) {
+        _defer = process.nextTick;
+    } else {
+        _defer = fallback;
+    }
+
+    var setImmediate$1 = wrap(_defer);
+
+    /**
+     * Take a sync function and make it async, passing its return value to a
+     * callback. This is useful for plugging sync functions into a waterfall,
+     * series, or other async functions. Any arguments passed to the generated
+     * function will be passed to the wrapped function (except for the final
+     * callback argument). Errors thrown will be passed to the callback.
+     *
+     * If the function passed to `asyncify` returns a Promise, that promises's
+     * resolved/rejected state will be used to call the callback, rather than simply
+     * the synchronous return value.
+     *
+     * This also means you can asyncify ES2017 `async` functions.
+     *
+     * @name asyncify
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @alias wrapSync
+     * @category Util
+     * @param {Function} func - The synchronous function, or Promise-returning
+     * function to convert to an {@link AsyncFunction}.
+     * @returns {AsyncFunction} An asynchronous wrapper of the `func`. To be
+     * invoked with `(args..., callback)`.
+     * @example
+     *
+     * // passing a regular synchronous function
+     * async.waterfall([
+     *     async.apply(fs.readFile, filename, "utf8"),
+     *     async.asyncify(JSON.parse),
+     *     function (data, next) {
+     *         // data is the result of parsing the text.
+     *         // If there was a parsing error, it would have been caught.
+     *     }
+     * ], callback);
+     *
+     * // passing a function returning a promise
+     * async.waterfall([
+     *     async.apply(fs.readFile, filename, "utf8"),
+     *     async.asyncify(function (contents) {
+     *         return db.model.create(contents);
+     *     }),
+     *     function (model, next) {
+     *         // `model` is the instantiated model object.
+     *         // If there was an error, this function would be skipped.
+     *     }
+     * ], callback);
+     *
+     * // es2017 example, though `asyncify` is not needed if your JS environment
+     * // supports async functions out of the box
+     * var q = async.queue(async.asyncify(async function(file) {
+     *     var intermediateStep = await processFile(file);
+     *     return await somePromise(intermediateStep)
+     * }));
+     *
+     * q.push(files);
+     */
+    function asyncify(func) {
+        if (isAsync(func)) {
+            return function (...args/*, callback*/) {
+                const callback = args.pop();
+                const promise = func.apply(this, args);
+                return handlePromise(promise, callback)
+            }
+        }
+
+        return initialParams(function (args, callback) {
+            var result;
+            try {
+                result = func.apply(this, args);
+            } catch (e) {
+                return callback(e);
+            }
+            // if result is Promise object
+            if (result && typeof result.then === 'function') {
+                return handlePromise(result, callback)
+            } else {
+                callback(null, result);
+            }
+        });
+    }
+
+    function handlePromise(promise, callback) {
+        return promise.then(value => {
+            invokeCallback(callback, null, value);
+        }, err => {
+            invokeCallback(callback, err && err.message ? err : new Error(err));
+        });
+    }
+
+    function invokeCallback(callback, error, value) {
+        try {
+            callback(error, value);
+        } catch (err) {
+            setImmediate$1(e => { throw e }, err);
+        }
+    }
+
+    function isAsync(fn) {
+        return fn[Symbol.toStringTag] === 'AsyncFunction';
+    }
+
+    function isAsyncGenerator(fn) {
+        return fn[Symbol.toStringTag] === 'AsyncGenerator';
+    }
+
+    function isAsyncIterable(obj) {
+        return typeof obj[Symbol.asyncIterator] === 'function';
+    }
+
+    function wrapAsync(asyncFn) {
+        if (typeof asyncFn !== 'function') throw new Error('expected a function')
+        return isAsync(asyncFn) ? asyncify(asyncFn) : asyncFn;
+    }
+
+    // conditionally promisify a function.
+    // only return a promise if a callback is omitted
+    function awaitify (asyncFn, arity = asyncFn.length) {
+        if (!arity) throw new Error('arity is undefined')
+        function awaitable (...args) {
+            if (typeof args[arity - 1] === 'function') {
+                return asyncFn.apply(this, args)
+            }
+
+            return new Promise((resolve, reject) => {
+                args[arity - 1] = (err, ...cbArgs) => {
+                    if (err) return reject(err)
+                    resolve(cbArgs.length > 1 ? cbArgs : cbArgs[0]);
+                };
+                asyncFn.apply(this, args);
+            })
+        }
+
+        return awaitable
+    }
+
+    function applyEach (eachfn) {
+        return function applyEach(fns, ...callArgs) {
+            const go = awaitify(function (callback) {
+                var that = this;
+                return eachfn(fns, (fn, cb) => {
+                    wrapAsync(fn).apply(that, callArgs.concat(cb));
+                }, callback);
+            });
+            return go;
+        };
+    }
+
+    function _asyncMap(eachfn, arr, iteratee, callback) {
+        arr = arr || [];
+        var results = [];
+        var counter = 0;
+        var _iteratee = wrapAsync(iteratee);
+
+        return eachfn(arr, (value, _, iterCb) => {
+            var index = counter++;
+            _iteratee(value, (err, v) => {
+                results[index] = v;
+                iterCb(err);
+            });
+        }, err => {
+            callback(err, results);
+        });
+    }
+
+    function isArrayLike(value) {
+        return value &&
+            typeof value.length === 'number' &&
+            value.length >= 0 &&
+            value.length % 1 === 0;
+    }
+
+    // A temporary value used to identify if the loop should be broken.
+    // See #1064, #1293
+    const breakLoop = {};
+
+    function once(fn) {
+        function wrapper (...args) {
+            if (fn === null) return;
+            var callFn = fn;
+            fn = null;
+            callFn.apply(this, args);
+        }
+        Object.assign(wrapper, fn);
+        return wrapper
+    }
+
+    function getIterator (coll) {
+        return coll[Symbol.iterator] && coll[Symbol.iterator]();
+    }
+
+    function createArrayIterator(coll) {
+        var i = -1;
+        var len = coll.length;
+        return function next() {
+            return ++i < len ? {value: coll[i], key: i} : null;
+        }
+    }
+
+    function createES2015Iterator(iterator) {
+        var i = -1;
+        return function next() {
+            var item = iterator.next();
+            if (item.done)
+                return null;
+            i++;
+            return {value: item.value, key: i};
+        }
+    }
+
+    function createObjectIterator(obj) {
+        var okeys = obj ? Object.keys(obj) : [];
+        var i = -1;
+        var len = okeys.length;
+        return function next() {
+            var key = okeys[++i];
+            if (key === '__proto__') {
+                return next();
+            }
+            return i < len ? {value: obj[key], key} : null;
+        };
+    }
+
+    function createIterator(coll) {
+        if (isArrayLike(coll)) {
+            return createArrayIterator(coll);
+        }
+
+        var iterator = getIterator(coll);
+        return iterator ? createES2015Iterator(iterator) : createObjectIterator(coll);
+    }
+
+    function onlyOnce(fn) {
+        return function (...args) {
+            if (fn === null) throw new Error("Callback was already called.");
+            var callFn = fn;
+            fn = null;
+            callFn.apply(this, args);
+        };
+    }
+
+    // for async generators
+    function asyncEachOfLimit(generator, limit, iteratee, callback) {
+        let done = false;
+        let canceled = false;
+        let awaiting = false;
+        let running = 0;
+        let idx = 0;
+
+        function replenish() {
+            //console.log('replenish')
+            if (running >= limit || awaiting || done) return
+            //console.log('replenish awaiting')
+            awaiting = true;
+            generator.next().then(({value, done: iterDone}) => {
+                //console.log('got value', value)
+                if (canceled || done) return
+                awaiting = false;
+                if (iterDone) {
+                    done = true;
+                    if (running <= 0) {
+                        //console.log('done nextCb')
+                        callback(null);
+                    }
+                    return;
+                }
+                running++;
+                iteratee(value, idx, iterateeCallback);
+                idx++;
+                replenish();
+            }).catch(handleError);
+        }
+
+        function iterateeCallback(err, result) {
+            //console.log('iterateeCallback')
+            running -= 1;
+            if (canceled) return
+            if (err) return handleError(err)
+
+            if (err === false) {
+                done = true;
+                canceled = true;
+                return
+            }
+
+            if (result === breakLoop || (done && running <= 0)) {
+                done = true;
+                //console.log('done iterCb')
+                return callback(null);
+            }
+            replenish();
+        }
+
+        function handleError(err) {
+            if (canceled) return
+            awaiting = false;
+            done = true;
+            callback(err);
+        }
+
+        replenish();
+    }
+
+    var eachOfLimit = (limit) => {
+        return (obj, iteratee, callback) => {
+            callback = once(callback);
+            if (limit <= 0) {
+                throw new RangeError('concurrency limit cannot be less than 1')
+            }
+            if (!obj) {
+                return callback(null);
+            }
+            if (isAsyncGenerator(obj)) {
+                return asyncEachOfLimit(obj, limit, iteratee, callback)
+            }
+            if (isAsyncIterable(obj)) {
+                return asyncEachOfLimit(obj[Symbol.asyncIterator](), limit, iteratee, callback)
+            }
+            var nextElem = createIterator(obj);
+            var done = false;
+            var canceled = false;
+            var running = 0;
+            var looping = false;
+
+            function iterateeCallback(err, value) {
+                if (canceled) return
+                running -= 1;
+                if (err) {
+                    done = true;
+                    callback(err);
+                }
+                else if (err === false) {
+                    done = true;
+                    canceled = true;
+                }
+                else if (value === breakLoop || (done && running <= 0)) {
+                    done = true;
+                    return callback(null);
+                }
+                else if (!looping) {
+                    replenish();
+                }
+            }
+
+            function replenish () {
+                looping = true;
+                while (running < limit && !done) {
+                    var elem = nextElem();
+                    if (elem === null) {
+                        done = true;
+                        if (running <= 0) {
+                            callback(null);
+                        }
+                        return;
+                    }
+                    running += 1;
+                    iteratee(elem.value, elem.key, onlyOnce(iterateeCallback));
+                }
+                looping = false;
+            }
+
+            replenish();
+        };
+    };
+
+    /**
+     * The same as [`eachOf`]{@link module:Collections.eachOf} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name eachOfLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.eachOf]{@link module:Collections.eachOf}
+     * @alias forEachOfLimit
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - An async function to apply to each
+     * item in `coll`. The `key` is the item's key, or index in the case of an
+     * array.
+     * Invoked with (item, key, callback).
+     * @param {Function} [callback] - A callback which is called when all
+     * `iteratee` functions have finished, or an error occurs. Invoked with (err).
+     * @returns {Promise} a promise, if a callback is omitted
+     */
+    function eachOfLimit$1(coll, limit, iteratee, callback) {
+        return eachOfLimit(limit)(coll, wrapAsync(iteratee), callback);
+    }
+
+    var eachOfLimit$2 = awaitify(eachOfLimit$1, 4);
+
+    // eachOf implementation optimized for array-likes
+    function eachOfArrayLike(coll, iteratee, callback) {
+        callback = once(callback);
+        var index = 0,
+            completed = 0,
+            {length} = coll,
+            canceled = false;
+        if (length === 0) {
+            callback(null);
+        }
+
+        function iteratorCallback(err, value) {
+            if (err === false) {
+                canceled = true;
+            }
+            if (canceled === true) return
+            if (err) {
+                callback(err);
+            } else if ((++completed === length) || value === breakLoop) {
+                callback(null);
+            }
+        }
+
+        for (; index < length; index++) {
+            iteratee(coll[index], index, onlyOnce(iteratorCallback));
+        }
+    }
+
+    // a generic version of eachOf which can handle array, object, and iterator cases.
+    function eachOfGeneric (coll, iteratee, callback) {
+        return eachOfLimit$2(coll, Infinity, iteratee, callback);
+    }
+
+    /**
+     * Like [`each`]{@link module:Collections.each}, except that it passes the key (or index) as the second argument
+     * to the iteratee.
+     *
+     * @name eachOf
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias forEachOf
+     * @category Collection
+     * @see [async.each]{@link module:Collections.each}
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A function to apply to each
+     * item in `coll`.
+     * The `key` is the item's key, or index in the case of an array.
+     * Invoked with (item, key, callback).
+     * @param {Function} [callback] - A callback which is called when all
+     * `iteratee` functions have finished, or an error occurs. Invoked with (err).
+     * @returns {Promise} a promise, if a callback is omitted
+     * @example
+     *
+     * // dev.json is a file containing a valid json object config for dev environment
+     * // dev.json is a file containing a valid json object config for test environment
+     * // prod.json is a file containing a valid json object config for prod environment
+     * // invalid.json is a file with a malformed json object
+     *
+     * let configs = {}; //global variable
+     * let validConfigFileMap = {dev: 'dev.json', test: 'test.json', prod: 'prod.json'};
+     * let invalidConfigFileMap = {dev: 'dev.json', test: 'test.json', invalid: 'invalid.json'};
+     *
+     * // asynchronous function that reads a json file and parses the contents as json object
+     * function parseFile(file, key, callback) {
+     *     fs.readFile(file, "utf8", function(err, data) {
+     *         if (err) return calback(err);
+     *         try {
+     *             configs[key] = JSON.parse(data);
+     *         } catch (e) {
+     *             return callback(e);
+     *         }
+     *         callback();
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.forEachOf(validConfigFileMap, parseFile, function (err) {
+     *     if (err) {
+     *         console.error(err);
+     *     } else {
+     *         console.log(configs);
+     *         // configs is now a map of JSON data, e.g.
+     *         // { dev: //parsed dev.json, test: //parsed test.json, prod: //parsed prod.json}
+     *     }
+     * });
+     *
+     * //Error handing
+     * async.forEachOf(invalidConfigFileMap, parseFile, function (err) {
+     *     if (err) {
+     *         console.error(err);
+     *         // JSON parse error exception
+     *     } else {
+     *         console.log(configs);
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.forEachOf(validConfigFileMap, parseFile)
+     * .then( () => {
+     *     console.log(configs);
+     *     // configs is now a map of JSON data, e.g.
+     *     // { dev: //parsed dev.json, test: //parsed test.json, prod: //parsed prod.json}
+     * }).catch( err => {
+     *     console.error(err);
+     * });
+     *
+     * //Error handing
+     * async.forEachOf(invalidConfigFileMap, parseFile)
+     * .then( () => {
+     *     console.log(configs);
+     * }).catch( err => {
+     *     console.error(err);
+     *     // JSON parse error exception
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.forEachOf(validConfigFileMap, parseFile);
+     *         console.log(configs);
+     *         // configs is now a map of JSON data, e.g.
+     *         // { dev: //parsed dev.json, test: //parsed test.json, prod: //parsed prod.json}
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * //Error handing
+     * async () => {
+     *     try {
+     *         let result = await async.forEachOf(invalidConfigFileMap, parseFile);
+     *         console.log(configs);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *         // JSON parse error exception
+     *     }
+     * }
+     *
+     */
+    function eachOf(coll, iteratee, callback) {
+        var eachOfImplementation = isArrayLike(coll) ? eachOfArrayLike : eachOfGeneric;
+        return eachOfImplementation(coll, wrapAsync(iteratee), callback);
+    }
+
+    var eachOf$1 = awaitify(eachOf, 3);
+
+    /**
+     * Produces a new collection of values by mapping each value in `coll` through
+     * the `iteratee` function. The `iteratee` is called with an item from `coll`
+     * and a callback for when it has finished processing. Each of these callbacks
+     * takes 2 arguments: an `error`, and the transformed item from `coll`. If
+     * `iteratee` passes an error to its callback, the main `callback` (for the
+     * `map` function) is immediately called with the error.
+     *
+     * Note, that since this function applies the `iteratee` to each item in
+     * parallel, there is no guarantee that the `iteratee` functions will complete
+     * in order. However, the results array will be in the same order as the
+     * original `coll`.
+     *
+     * If `map` is passed an Object, the results will be an Array.  The results
+     * will roughly be in the order of the original Objects' keys (but this can
+     * vary across JavaScript engines).
+     *
+     * @name map
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with the transformed item.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Results is an Array of the
+     * transformed items from the `coll`. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * // file1.txt is a file that is 1000 bytes in size
+     * // file2.txt is a file that is 2000 bytes in size
+     * // file3.txt is a file that is 3000 bytes in size
+     * // file4.txt does not exist
+     *
+     * const fileList = ['file1.txt','file2.txt','file3.txt'];
+     * const withMissingFileList = ['file1.txt','file2.txt','file4.txt'];
+     *
+     * // asynchronous function that returns the file size in bytes
+     * function getFileSizeInBytes(file, callback) {
+     *     fs.stat(file, function(err, stat) {
+     *         if (err) {
+     *             return callback(err);
+     *         }
+     *         callback(null, stat.size);
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.map(fileList, getFileSizeInBytes, function(err, results) {
+     *     if (err) {
+     *         console.log(err);
+     *     } else {
+     *         console.log(results);
+     *         // results is now an array of the file size in bytes for each file, e.g.
+     *         // [ 1000, 2000, 3000]
+     *     }
+     * });
+     *
+     * // Error Handling
+     * async.map(withMissingFileList, getFileSizeInBytes, function(err, results) {
+     *     if (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     } else {
+     *         console.log(results);
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.map(fileList, getFileSizeInBytes)
+     * .then( results => {
+     *     console.log(results);
+     *     // results is now an array of the file size in bytes for each file, e.g.
+     *     // [ 1000, 2000, 3000]
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Error Handling
+     * async.map(withMissingFileList, getFileSizeInBytes)
+     * .then( results => {
+     *     console.log(results);
+     * }).catch( err => {
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.map(fileList, getFileSizeInBytes);
+     *         console.log(results);
+     *         // results is now an array of the file size in bytes for each file, e.g.
+     *         // [ 1000, 2000, 3000]
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // Error Handling
+     * async () => {
+     *     try {
+     *         let results = await async.map(withMissingFileList, getFileSizeInBytes);
+     *         console.log(results);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     }
+     * }
+     *
+     */
+    function map (coll, iteratee, callback) {
+        return _asyncMap(eachOf$1, coll, iteratee, callback)
+    }
+    var map$1 = awaitify(map, 3);
+
+    /**
+     * Applies the provided arguments to each function in the array, calling
+     * `callback` after all functions have completed. If you only provide the first
+     * argument, `fns`, then it will return a function which lets you pass in the
+     * arguments as if it were a single function call. If more arguments are
+     * provided, `callback` is required while `args` is still optional. The results
+     * for each of the applied async functions are passed to the final callback
+     * as an array.
+     *
+     * @name applyEach
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Array|Iterable|AsyncIterable|Object} fns - A collection of {@link AsyncFunction}s
+     * to all call with the same arguments
+     * @param {...*} [args] - any number of separate arguments to pass to the
+     * function.
+     * @param {Function} [callback] - the final argument should be the callback,
+     * called when all functions have completed processing.
+     * @returns {AsyncFunction} - Returns a function that takes no args other than
+     * an optional callback, that is the result of applying the `args` to each
+     * of the functions.
+     * @example
+     *
+     * const appliedFn = async.applyEach([enableSearch, updateSchema], 'bucket')
+     *
+     * appliedFn((err, results) => {
+     *     // results[0] is the results for `enableSearch`
+     *     // results[1] is the results for `updateSchema`
+     * });
+     *
+     * // partial application example:
+     * async.each(
+     *     buckets,
+     *     async (bucket) => async.applyEach([enableSearch, updateSchema], bucket)(),
+     *     callback
+     * );
+     */
+    var applyEach$1 = applyEach(map$1);
+
+    /**
+     * The same as [`eachOf`]{@link module:Collections.eachOf} but runs only a single async operation at a time.
+     *
+     * @name eachOfSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.eachOf]{@link module:Collections.eachOf}
+     * @alias forEachOfSeries
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * Invoked with (item, key, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Invoked with (err).
+     * @returns {Promise} a promise, if a callback is omitted
+     */
+    function eachOfSeries(coll, iteratee, callback) {
+        return eachOfLimit$2(coll, 1, iteratee, callback)
+    }
+    var eachOfSeries$1 = awaitify(eachOfSeries, 3);
+
+    /**
+     * The same as [`map`]{@link module:Collections.map} but runs only a single async operation at a time.
+     *
+     * @name mapSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.map]{@link module:Collections.map}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with the transformed item.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Results is an array of the
+     * transformed items from the `coll`. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function mapSeries (coll, iteratee, callback) {
+        return _asyncMap(eachOfSeries$1, coll, iteratee, callback)
+    }
+    var mapSeries$1 = awaitify(mapSeries, 3);
+
+    /**
+     * The same as [`applyEach`]{@link module:ControlFlow.applyEach} but runs only a single async operation at a time.
+     *
+     * @name applyEachSeries
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.applyEach]{@link module:ControlFlow.applyEach}
+     * @category Control Flow
+     * @param {Array|Iterable|AsyncIterable|Object} fns - A collection of {@link AsyncFunction}s to all
+     * call with the same arguments
+     * @param {...*} [args] - any number of separate arguments to pass to the
+     * function.
+     * @param {Function} [callback] - the final argument should be the callback,
+     * called when all functions have completed processing.
+     * @returns {AsyncFunction} - A function, that when called, is the result of
+     * appling the `args` to the list of functions.  It takes no args, other than
+     * a callback.
+     */
+    var applyEachSeries = applyEach(mapSeries$1);
+
+    const PROMISE_SYMBOL = Symbol('promiseCallback');
+
+    function promiseCallback () {
+        let resolve, reject;
+        function callback (err, ...args) {
+            if (err) return reject(err)
+            resolve(args.length > 1 ? args : args[0]);
+        }
+
+        callback[PROMISE_SYMBOL] = new Promise((res, rej) => {
+            resolve = res,
+            reject = rej;
+        });
+
+        return callback
+    }
+
+    /**
+     * Determines the best order for running the {@link AsyncFunction}s in `tasks`, based on
+     * their requirements. Each function can optionally depend on other functions
+     * being completed first, and each function is run as soon as its requirements
+     * are satisfied.
+     *
+     * If any of the {@link AsyncFunction}s pass an error to their callback, the `auto` sequence
+     * will stop. Further tasks will not execute (so any other functions depending
+     * on it will not run), and the main `callback` is immediately called with the
+     * error.
+     *
+     * {@link AsyncFunction}s also receive an object containing the results of functions which
+     * have completed so far as the first argument, if they have dependencies. If a
+     * task function has no dependencies, it will only be passed a callback.
+     *
+     * @name auto
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Object} tasks - An object. Each of its properties is either a
+     * function or an array of requirements, with the {@link AsyncFunction} itself the last item
+     * in the array. The object's key of a property serves as the name of the task
+     * defined by that property, i.e. can be used when specifying requirements for
+     * other tasks. The function receives one or two arguments:
+     * * a `results` object, containing the results of the previously executed
+     *   functions, only passed if the task has any dependencies,
+     * * a `callback(err, result)` function, which must be called when finished,
+     *   passing an `error` (which can be `null`) and the result of the function's
+     *   execution.
+     * @param {number} [concurrency=Infinity] - An optional `integer` for
+     * determining the maximum number of tasks that can be run in parallel. By
+     * default, as many as possible.
+     * @param {Function} [callback] - An optional callback which is called when all
+     * the tasks have been completed. It receives the `err` argument if any `tasks`
+     * pass an error to their callback. Results are always returned; however, if an
+     * error occurs, no further `tasks` will be performed, and the results object
+     * will only contain partial results. Invoked with (err, results).
+     * @returns {Promise} a promise, if a callback is not passed
+     * @example
+     *
+     * //Using Callbacks
+     * async.auto({
+     *     get_data: function(callback) {
+     *         // async code to get some data
+     *         callback(null, 'data', 'converted to array');
+     *     },
+     *     make_folder: function(callback) {
+     *         // async code to create a directory to store a file in
+     *         // this is run at the same time as getting the data
+     *         callback(null, 'folder');
+     *     },
+     *     write_file: ['get_data', 'make_folder', function(results, callback) {
+     *         // once there is some data and the directory exists,
+     *         // write the data to a file in the directory
+     *         callback(null, 'filename');
+     *     }],
+     *     email_link: ['write_file', function(results, callback) {
+     *         // once the file is written let's email a link to it...
+     *         callback(null, {'file':results.write_file, 'email':'user@example.com'});
+     *     }]
+     * }, function(err, results) {
+     *     if (err) {
+     *         console.log('err = ', err);
+     *     }
+     *     console.log('results = ', results);
+     *     // results = {
+     *     //     get_data: ['data', 'converted to array']
+     *     //     make_folder; 'folder',
+     *     //     write_file: 'filename'
+     *     //     email_link: { file: 'filename', email: 'user@example.com' }
+     *     // }
+     * });
+     *
+     * //Using Promises
+     * async.auto({
+     *     get_data: function(callback) {
+     *         console.log('in get_data');
+     *         // async code to get some data
+     *         callback(null, 'data', 'converted to array');
+     *     },
+     *     make_folder: function(callback) {
+     *         console.log('in make_folder');
+     *         // async code to create a directory to store a file in
+     *         // this is run at the same time as getting the data
+     *         callback(null, 'folder');
+     *     },
+     *     write_file: ['get_data', 'make_folder', function(results, callback) {
+     *         // once there is some data and the directory exists,
+     *         // write the data to a file in the directory
+     *         callback(null, 'filename');
+     *     }],
+     *     email_link: ['write_file', function(results, callback) {
+     *         // once the file is written let's email a link to it...
+     *         callback(null, {'file':results.write_file, 'email':'user@example.com'});
+     *     }]
+     * }).then(results => {
+     *     console.log('results = ', results);
+     *     // results = {
+     *     //     get_data: ['data', 'converted to array']
+     *     //     make_folder; 'folder',
+     *     //     write_file: 'filename'
+     *     //     email_link: { file: 'filename', email: 'user@example.com' }
+     *     // }
+     * }).catch(err => {
+     *     console.log('err = ', err);
+     * });
+     *
+     * //Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.auto({
+     *             get_data: function(callback) {
+     *                 // async code to get some data
+     *                 callback(null, 'data', 'converted to array');
+     *             },
+     *             make_folder: function(callback) {
+     *                 // async code to create a directory to store a file in
+     *                 // this is run at the same time as getting the data
+     *                 callback(null, 'folder');
+     *             },
+     *             write_file: ['get_data', 'make_folder', function(results, callback) {
+     *                 // once there is some data and the directory exists,
+     *                 // write the data to a file in the directory
+     *                 callback(null, 'filename');
+     *             }],
+     *             email_link: ['write_file', function(results, callback) {
+     *                 // once the file is written let's email a link to it...
+     *                 callback(null, {'file':results.write_file, 'email':'user@example.com'});
+     *             }]
+     *         });
+     *         console.log('results = ', results);
+     *         // results = {
+     *         //     get_data: ['data', 'converted to array']
+     *         //     make_folder; 'folder',
+     *         //     write_file: 'filename'
+     *         //     email_link: { file: 'filename', email: 'user@example.com' }
+     *         // }
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function auto(tasks, concurrency, callback) {
+        if (typeof concurrency !== 'number') {
+            // concurrency is optional, shift the args.
+            callback = concurrency;
+            concurrency = null;
+        }
+        callback = once(callback || promiseCallback());
+        var numTasks = Object.keys(tasks).length;
+        if (!numTasks) {
+            return callback(null);
+        }
+        if (!concurrency) {
+            concurrency = numTasks;
+        }
+
+        var results = {};
+        var runningTasks = 0;
+        var canceled = false;
+        var hasError = false;
+
+        var listeners = Object.create(null);
+
+        var readyTasks = [];
+
+        // for cycle detection:
+        var readyToCheck = []; // tasks that have been identified as reachable
+        // without the possibility of returning to an ancestor task
+        var uncheckedDependencies = {};
+
+        Object.keys(tasks).forEach(key => {
+            var task = tasks[key];
+            if (!Array.isArray(task)) {
+                // no dependencies
+                enqueueTask(key, [task]);
+                readyToCheck.push(key);
+                return;
+            }
+
+            var dependencies = task.slice(0, task.length - 1);
+            var remainingDependencies = dependencies.length;
+            if (remainingDependencies === 0) {
+                enqueueTask(key, task);
+                readyToCheck.push(key);
+                return;
+            }
+            uncheckedDependencies[key] = remainingDependencies;
+
+            dependencies.forEach(dependencyName => {
+                if (!tasks[dependencyName]) {
+                    throw new Error('async.auto task `' + key +
+                        '` has a non-existent dependency `' +
+                        dependencyName + '` in ' +
+                        dependencies.join(', '));
+                }
+                addListener(dependencyName, () => {
+                    remainingDependencies--;
+                    if (remainingDependencies === 0) {
+                        enqueueTask(key, task);
+                    }
+                });
+            });
+        });
+
+        checkForDeadlocks();
+        processQueue();
+
+        function enqueueTask(key, task) {
+            readyTasks.push(() => runTask(key, task));
+        }
+
+        function processQueue() {
+            if (canceled) return
+            if (readyTasks.length === 0 && runningTasks === 0) {
+                return callback(null, results);
+            }
+            while(readyTasks.length && runningTasks < concurrency) {
+                var run = readyTasks.shift();
+                run();
+            }
+
+        }
+
+        function addListener(taskName, fn) {
+            var taskListeners = listeners[taskName];
+            if (!taskListeners) {
+                taskListeners = listeners[taskName] = [];
+            }
+
+            taskListeners.push(fn);
+        }
+
+        function taskComplete(taskName) {
+            var taskListeners = listeners[taskName] || [];
+            taskListeners.forEach(fn => fn());
+            processQueue();
+        }
+
+
+        function runTask(key, task) {
+            if (hasError) return;
+
+            var taskCallback = onlyOnce((err, ...result) => {
+                runningTasks--;
+                if (err === false) {
+                    canceled = true;
+                    return
+                }
+                if (result.length < 2) {
+                    [result] = result;
+                }
+                if (err) {
+                    var safeResults = {};
+                    Object.keys(results).forEach(rkey => {
+                        safeResults[rkey] = results[rkey];
+                    });
+                    safeResults[key] = result;
+                    hasError = true;
+                    listeners = Object.create(null);
+                    if (canceled) return
+                    callback(err, safeResults);
+                } else {
+                    results[key] = result;
+                    taskComplete(key);
+                }
+            });
+
+            runningTasks++;
+            var taskFn = wrapAsync(task[task.length - 1]);
+            if (task.length > 1) {
+                taskFn(results, taskCallback);
+            } else {
+                taskFn(taskCallback);
+            }
+        }
+
+        function checkForDeadlocks() {
+            // Kahn's algorithm
+            // https://en.wikipedia.org/wiki/Topological_sorting#Kahn.27s_algorithm
+            // http://connalle.blogspot.com/2013/10/topological-sortingkahn-algorithm.html
+            var currentTask;
+            var counter = 0;
+            while (readyToCheck.length) {
+                currentTask = readyToCheck.pop();
+                counter++;
+                getDependents(currentTask).forEach(dependent => {
+                    if (--uncheckedDependencies[dependent] === 0) {
+                        readyToCheck.push(dependent);
+                    }
+                });
+            }
+
+            if (counter !== numTasks) {
+                throw new Error(
+                    'async.auto cannot execute tasks due to a recursive dependency'
+                );
+            }
+        }
+
+        function getDependents(taskName) {
+            var result = [];
+            Object.keys(tasks).forEach(key => {
+                const task = tasks[key];
+                if (Array.isArray(task) && task.indexOf(taskName) >= 0) {
+                    result.push(key);
+                }
+            });
+            return result;
+        }
+
+        return callback[PROMISE_SYMBOL]
+    }
+
+    var FN_ARGS = /^(?:async\s+)?(?:function)?\s*\w*\s*\(\s*([^)]+)\s*\)(?:\s*{)/;
+    var ARROW_FN_ARGS = /^(?:async\s+)?\(?\s*([^)=]+)\s*\)?(?:\s*=>)/;
+    var FN_ARG_SPLIT = /,/;
+    var FN_ARG = /(=.+)?(\s*)$/;
+
+    function stripComments(string) {
+        let stripped = '';
+        let index = 0;
+        let endBlockComment = string.indexOf('*/');
+        while (index < string.length) {
+            if (string[index] === '/' && string[index+1] === '/') {
+                // inline comment
+                let endIndex = string.indexOf('\n', index);
+                index = (endIndex === -1) ? string.length : endIndex;
+            } else if ((endBlockComment !== -1) && (string[index] === '/') && (string[index+1] === '*')) {
+                // block comment
+                let endIndex = string.indexOf('*/', index);
+                if (endIndex !== -1) {
+                    index = endIndex + 2;
+                    endBlockComment = string.indexOf('*/', index);
+                } else {
+                    stripped += string[index];
+                    index++;
+                }
+            } else {
+                stripped += string[index];
+                index++;
+            }
+        }
+        return stripped;
+    }
+
+    function parseParams(func) {
+        const src = stripComments(func.toString());
+        let match = src.match(FN_ARGS);
+        if (!match) {
+            match = src.match(ARROW_FN_ARGS);
+        }
+        if (!match) throw new Error('could not parse args in autoInject\nSource:\n' + src)
+        let [, args] = match;
+        return args
+            .replace(/\s/g, '')
+            .split(FN_ARG_SPLIT)
+            .map((arg) => arg.replace(FN_ARG, '').trim());
+    }
+
+    /**
+     * A dependency-injected version of the [async.auto]{@link module:ControlFlow.auto} function. Dependent
+     * tasks are specified as parameters to the function, after the usual callback
+     * parameter, with the parameter names matching the names of the tasks it
+     * depends on. This can provide even more readable task graphs which can be
+     * easier to maintain.
+     *
+     * If a final callback is specified, the task results are similarly injected,
+     * specified as named parameters after the initial error parameter.
+     *
+     * The autoInject function is purely syntactic sugar and its semantics are
+     * otherwise equivalent to [async.auto]{@link module:ControlFlow.auto}.
+     *
+     * @name autoInject
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.auto]{@link module:ControlFlow.auto}
+     * @category Control Flow
+     * @param {Object} tasks - An object, each of whose properties is an {@link AsyncFunction} of
+     * the form 'func([dependencies...], callback). The object's key of a property
+     * serves as the name of the task defined by that property, i.e. can be used
+     * when specifying requirements for other tasks.
+     * * The `callback` parameter is a `callback(err, result)` which must be called
+     *   when finished, passing an `error` (which can be `null`) and the result of
+     *   the function's execution. The remaining parameters name other tasks on
+     *   which the task is dependent, and the results from those tasks are the
+     *   arguments of those parameters.
+     * @param {Function} [callback] - An optional callback which is called when all
+     * the tasks have been completed. It receives the `err` argument if any `tasks`
+     * pass an error to their callback, and a `results` object with any completed
+     * task results, similar to `auto`.
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * //  The example from `auto` can be rewritten as follows:
+     * async.autoInject({
+     *     get_data: function(callback) {
+     *         // async code to get some data
+     *         callback(null, 'data', 'converted to array');
+     *     },
+     *     make_folder: function(callback) {
+     *         // async code to create a directory to store a file in
+     *         // this is run at the same time as getting the data
+     *         callback(null, 'folder');
+     *     },
+     *     write_file: function(get_data, make_folder, callback) {
+     *         // once there is some data and the directory exists,
+     *         // write the data to a file in the directory
+     *         callback(null, 'filename');
+     *     },
+     *     email_link: function(write_file, callback) {
+     *         // once the file is written let's email a link to it...
+     *         // write_file contains the filename returned by write_file.
+     *         callback(null, {'file':write_file, 'email':'user@example.com'});
+     *     }
+     * }, function(err, results) {
+     *     console.log('err = ', err);
+     *     console.log('email_link = ', results.email_link);
+     * });
+     *
+     * // If you are using a JS minifier that mangles parameter names, `autoInject`
+     * // will not work with plain functions, since the parameter names will be
+     * // collapsed to a single letter identifier.  To work around this, you can
+     * // explicitly specify the names of the parameters your task function needs
+     * // in an array, similar to Angular.js dependency injection.
+     *
+     * // This still has an advantage over plain `auto`, since the results a task
+     * // depends on are still spread into arguments.
+     * async.autoInject({
+     *     //...
+     *     write_file: ['get_data', 'make_folder', function(get_data, make_folder, callback) {
+     *         callback(null, 'filename');
+     *     }],
+     *     email_link: ['write_file', function(write_file, callback) {
+     *         callback(null, {'file':write_file, 'email':'user@example.com'});
+     *     }]
+     *     //...
+     * }, function(err, results) {
+     *     console.log('err = ', err);
+     *     console.log('email_link = ', results.email_link);
+     * });
+     */
+    function autoInject(tasks, callback) {
+        var newTasks = {};
+
+        Object.keys(tasks).forEach(key => {
+            var taskFn = tasks[key];
+            var params;
+            var fnIsAsync = isAsync(taskFn);
+            var hasNoDeps =
+                (!fnIsAsync && taskFn.length === 1) ||
+                (fnIsAsync && taskFn.length === 0);
+
+            if (Array.isArray(taskFn)) {
+                params = [...taskFn];
+                taskFn = params.pop();
+
+                newTasks[key] = params.concat(params.length > 0 ? newTask : taskFn);
+            } else if (hasNoDeps) {
+                // no dependencies, use the function as-is
+                newTasks[key] = taskFn;
+            } else {
+                params = parseParams(taskFn);
+                if ((taskFn.length === 0 && !fnIsAsync) && params.length === 0) {
+                    throw new Error("autoInject task functions require explicit parameters.");
+                }
+
+                // remove callback param
+                if (!fnIsAsync) params.pop();
+
+                newTasks[key] = params.concat(newTask);
+            }
+
+            function newTask(results, taskCb) {
+                var newArgs = params.map(name => results[name]);
+                newArgs.push(taskCb);
+                wrapAsync(taskFn)(...newArgs);
+            }
+        });
+
+        return auto(newTasks, callback);
+    }
+
+    // Simple doubly linked list (https://en.wikipedia.org/wiki/Doubly_linked_list) implementation
+    // used for queues. This implementation assumes that the node provided by the user can be modified
+    // to adjust the next and last properties. We implement only the minimal functionality
+    // for queue support.
+    class DLL {
+        constructor() {
+            this.head = this.tail = null;
+            this.length = 0;
+        }
+
+        removeLink(node) {
+            if (node.prev) node.prev.next = node.next;
+            else this.head = node.next;
+            if (node.next) node.next.prev = node.prev;
+            else this.tail = node.prev;
+
+            node.prev = node.next = null;
+            this.length -= 1;
+            return node;
+        }
+
+        empty () {
+            while(this.head) this.shift();
+            return this;
+        }
+
+        insertAfter(node, newNode) {
+            newNode.prev = node;
+            newNode.next = node.next;
+            if (node.next) node.next.prev = newNode;
+            else this.tail = newNode;
+            node.next = newNode;
+            this.length += 1;
+        }
+
+        insertBefore(node, newNode) {
+            newNode.prev = node.prev;
+            newNode.next = node;
+            if (node.prev) node.prev.next = newNode;
+            else this.head = newNode;
+            node.prev = newNode;
+            this.length += 1;
+        }
+
+        unshift(node) {
+            if (this.head) this.insertBefore(this.head, node);
+            else setInitial(this, node);
+        }
+
+        push(node) {
+            if (this.tail) this.insertAfter(this.tail, node);
+            else setInitial(this, node);
+        }
+
+        shift() {
+            return this.head && this.removeLink(this.head);
+        }
+
+        pop() {
+            return this.tail && this.removeLink(this.tail);
+        }
+
+        toArray() {
+            return [...this]
+        }
+
+        *[Symbol.iterator] () {
+            var cur = this.head;
+            while (cur) {
+                yield cur.data;
+                cur = cur.next;
+            }
+        }
+
+        remove (testFn) {
+            var curr = this.head;
+            while(curr) {
+                var {next} = curr;
+                if (testFn(curr)) {
+                    this.removeLink(curr);
+                }
+                curr = next;
+            }
+            return this;
+        }
+    }
+
+    function setInitial(dll, node) {
+        dll.length = 1;
+        dll.head = dll.tail = node;
+    }
+
+    function queue(worker, concurrency, payload) {
+        if (concurrency == null) {
+            concurrency = 1;
+        }
+        else if(concurrency === 0) {
+            throw new RangeError('Concurrency must not be zero');
+        }
+
+        var _worker = wrapAsync(worker);
+        var numRunning = 0;
+        var workersList = [];
+        const events = {
+            error: [],
+            drain: [],
+            saturated: [],
+            unsaturated: [],
+            empty: []
+        };
+
+        function on (event, handler) {
+            events[event].push(handler);
+        }
+
+        function once (event, handler) {
+            const handleAndRemove = (...args) => {
+                off(event, handleAndRemove);
+                handler(...args);
+            };
+            events[event].push(handleAndRemove);
+        }
+
+        function off (event, handler) {
+            if (!event) return Object.keys(events).forEach(ev => events[ev] = [])
+            if (!handler) return events[event] = []
+            events[event] = events[event].filter(ev => ev !== handler);
+        }
+
+        function trigger (event, ...args) {
+            events[event].forEach(handler => handler(...args));
+        }
+
+        var processingScheduled = false;
+        function _insert(data, insertAtFront, rejectOnError, callback) {
+            if (callback != null && typeof callback !== 'function') {
+                throw new Error('task callback must be a function');
+            }
+            q.started = true;
+
+            var res, rej;
+            function promiseCallback (err, ...args) {
+                // we don't care about the error, let the global error handler
+                // deal with it
+                if (err) return rejectOnError ? rej(err) : res()
+                if (args.length <= 1) return res(args[0])
+                res(args);
+            }
+
+            var item = q._createTaskItem(
+                data,
+                rejectOnError ? promiseCallback :
+                    (callback || promiseCallback)
+            );
+
+            if (insertAtFront) {
+                q._tasks.unshift(item);
+            } else {
+                q._tasks.push(item);
+            }
+
+            if (!processingScheduled) {
+                processingScheduled = true;
+                setImmediate$1(() => {
+                    processingScheduled = false;
+                    q.process();
+                });
+            }
+
+            if (rejectOnError || !callback) {
+                return new Promise((resolve, reject) => {
+                    res = resolve;
+                    rej = reject;
+                })
+            }
+        }
+
+        function _createCB(tasks) {
+            return function (err, ...args) {
+                numRunning -= 1;
+
+                for (var i = 0, l = tasks.length; i < l; i++) {
+                    var task = tasks[i];
+
+                    var index = workersList.indexOf(task);
+                    if (index === 0) {
+                        workersList.shift();
+                    } else if (index > 0) {
+                        workersList.splice(index, 1);
+                    }
+
+                    task.callback(err, ...args);
+
+                    if (err != null) {
+                        trigger('error', err, task.data);
+                    }
+                }
+
+                if (numRunning <= (q.concurrency - q.buffer) ) {
+                    trigger('unsaturated');
+                }
+
+                if (q.idle()) {
+                    trigger('drain');
+                }
+                q.process();
+            };
+        }
+
+        function _maybeDrain(data) {
+            if (data.length === 0 && q.idle()) {
+                // call drain immediately if there are no tasks
+                setImmediate$1(() => trigger('drain'));
+                return true
+            }
+            return false
+        }
+
+        const eventMethod = (name) => (handler) => {
+            if (!handler) {
+                return new Promise((resolve, reject) => {
+                    once(name, (err, data) => {
+                        if (err) return reject(err)
+                        resolve(data);
+                    });
+                })
+            }
+            off(name);
+            on(name, handler);
+
+        };
+
+        var isProcessing = false;
+        var q = {
+            _tasks: new DLL(),
+            _createTaskItem (data, callback) {
+                return {
+                    data,
+                    callback
+                };
+            },
+            *[Symbol.iterator] () {
+                yield* q._tasks[Symbol.iterator]();
+            },
+            concurrency,
+            payload,
+            buffer: concurrency / 4,
+            started: false,
+            paused: false,
+            push (data, callback) {
+                if (Array.isArray(data)) {
+                    if (_maybeDrain(data)) return
+                    return data.map(datum => _insert(datum, false, false, callback))
+                }
+                return _insert(data, false, false, callback);
+            },
+            pushAsync (data, callback) {
+                if (Array.isArray(data)) {
+                    if (_maybeDrain(data)) return
+                    return data.map(datum => _insert(datum, false, true, callback))
+                }
+                return _insert(data, false, true, callback);
+            },
+            kill () {
+                off();
+                q._tasks.empty();
+            },
+            unshift (data, callback) {
+                if (Array.isArray(data)) {
+                    if (_maybeDrain(data)) return
+                    return data.map(datum => _insert(datum, true, false, callback))
+                }
+                return _insert(data, true, false, callback);
+            },
+            unshiftAsync (data, callback) {
+                if (Array.isArray(data)) {
+                    if (_maybeDrain(data)) return
+                    return data.map(datum => _insert(datum, true, true, callback))
+                }
+                return _insert(data, true, true, callback);
+            },
+            remove (testFn) {
+                q._tasks.remove(testFn);
+            },
+            process () {
+                // Avoid trying to start too many processing operations. This can occur
+                // when callbacks resolve synchronously (#1267).
+                if (isProcessing) {
+                    return;
+                }
+                isProcessing = true;
+                while(!q.paused && numRunning < q.concurrency && q._tasks.length){
+                    var tasks = [], data = [];
+                    var l = q._tasks.length;
+                    if (q.payload) l = Math.min(l, q.payload);
+                    for (var i = 0; i < l; i++) {
+                        var node = q._tasks.shift();
+                        tasks.push(node);
+                        workersList.push(node);
+                        data.push(node.data);
+                    }
+
+                    numRunning += 1;
+
+                    if (q._tasks.length === 0) {
+                        trigger('empty');
+                    }
+
+                    if (numRunning === q.concurrency) {
+                        trigger('saturated');
+                    }
+
+                    var cb = onlyOnce(_createCB(tasks));
+                    _worker(data, cb);
+                }
+                isProcessing = false;
+            },
+            length () {
+                return q._tasks.length;
+            },
+            running () {
+                return numRunning;
+            },
+            workersList () {
+                return workersList;
+            },
+            idle() {
+                return q._tasks.length + numRunning === 0;
+            },
+            pause () {
+                q.paused = true;
+            },
+            resume () {
+                if (q.paused === false) { return; }
+                q.paused = false;
+                setImmediate$1(q.process);
+            }
+        };
+        // define these as fixed properties, so people get useful errors when updating
+        Object.defineProperties(q, {
+            saturated: {
+                writable: false,
+                value: eventMethod('saturated')
+            },
+            unsaturated: {
+                writable: false,
+                value: eventMethod('unsaturated')
+            },
+            empty: {
+                writable: false,
+                value: eventMethod('empty')
+            },
+            drain: {
+                writable: false,
+                value: eventMethod('drain')
+            },
+            error: {
+                writable: false,
+                value: eventMethod('error')
+            },
+        });
+        return q;
+    }
+
+    /**
+     * Creates a `cargo` object with the specified payload. Tasks added to the
+     * cargo will be processed altogether (up to the `payload` limit). If the
+     * `worker` is in progress, the task is queued until it becomes available. Once
+     * the `worker` has completed some tasks, each callback of those tasks is
+     * called. Check out [these](https://camo.githubusercontent.com/6bbd36f4cf5b35a0f11a96dcd2e97711ffc2fb37/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130382f62626330636662302d356632392d313165322d393734662d3333393763363464633835382e676966) [animations](https://camo.githubusercontent.com/f4810e00e1c5f5f8addbe3e9f49064fd5d102699/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130312f38346339323036362d356632392d313165322d383134662d3964336430323431336266642e676966)
+     * for how `cargo` and `queue` work.
+     *
+     * While [`queue`]{@link module:ControlFlow.queue} passes only one task to one of a group of workers
+     * at a time, cargo passes an array of tasks to a single worker, repeating
+     * when the worker is finished.
+     *
+     * @name cargo
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.queue]{@link module:ControlFlow.queue}
+     * @category Control Flow
+     * @param {AsyncFunction} worker - An asynchronous function for processing an array
+     * of queued tasks. Invoked with `(tasks, callback)`.
+     * @param {number} [payload=Infinity] - An optional `integer` for determining
+     * how many tasks should be processed per round; if omitted, the default is
+     * unlimited.
+     * @returns {module:ControlFlow.QueueObject} A cargo object to manage the tasks. Callbacks can
+     * attached as certain properties to listen for specific events during the
+     * lifecycle of the cargo and inner queue.
+     * @example
+     *
+     * // create a cargo object with payload 2
+     * var cargo = async.cargo(function(tasks, callback) {
+     *     for (var i=0; i<tasks.length; i++) {
+     *         console.log('hello ' + tasks[i].name);
+     *     }
+     *     callback();
+     * }, 2);
+     *
+     * // add some items
+     * cargo.push({name: 'foo'}, function(err) {
+     *     console.log('finished processing foo');
+     * });
+     * cargo.push({name: 'bar'}, function(err) {
+     *     console.log('finished processing bar');
+     * });
+     * await cargo.push({name: 'baz'});
+     * console.log('finished processing baz');
+     */
+    function cargo(worker, payload) {
+        return queue(worker, 1, payload);
+    }
+
+    /**
+     * Creates a `cargoQueue` object with the specified payload. Tasks added to the
+     * cargoQueue will be processed together (up to the `payload` limit) in `concurrency` parallel workers.
+     * If the all `workers` are in progress, the task is queued until one becomes available. Once
+     * a `worker` has completed some tasks, each callback of those tasks is
+     * called. Check out [these](https://camo.githubusercontent.com/6bbd36f4cf5b35a0f11a96dcd2e97711ffc2fb37/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130382f62626330636662302d356632392d313165322d393734662d3333393763363464633835382e676966) [animations](https://camo.githubusercontent.com/f4810e00e1c5f5f8addbe3e9f49064fd5d102699/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f313637363837312f36383130312f38346339323036362d356632392d313165322d383134662d3964336430323431336266642e676966)
+     * for how `cargo` and `queue` work.
+     *
+     * While [`queue`]{@link module:ControlFlow.queue} passes only one task to one of a group of workers
+     * at a time, and [`cargo`]{@link module:ControlFlow.cargo} passes an array of tasks to a single worker,
+     * the cargoQueue passes an array of tasks to multiple parallel workers.
+     *
+     * @name cargoQueue
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.queue]{@link module:ControlFlow.queue}
+     * @see [async.cargo]{@link module:ControlFLow.cargo}
+     * @category Control Flow
+     * @param {AsyncFunction} worker - An asynchronous function for processing an array
+     * of queued tasks. Invoked with `(tasks, callback)`.
+     * @param {number} [concurrency=1] - An `integer` for determining how many
+     * `worker` functions should be run in parallel.  If omitted, the concurrency
+     * defaults to `1`.  If the concurrency is `0`, an error is thrown.
+     * @param {number} [payload=Infinity] - An optional `integer` for determining
+     * how many tasks should be processed per round; if omitted, the default is
+     * unlimited.
+     * @returns {module:ControlFlow.QueueObject} A cargoQueue object to manage the tasks. Callbacks can
+     * attached as certain properties to listen for specific events during the
+     * lifecycle of the cargoQueue and inner queue.
+     * @example
+     *
+     * // create a cargoQueue object with payload 2 and concurrency 2
+     * var cargoQueue = async.cargoQueue(function(tasks, callback) {
+     *     for (var i=0; i<tasks.length; i++) {
+     *         console.log('hello ' + tasks[i].name);
+     *     }
+     *     callback();
+     * }, 2, 2);
+     *
+     * // add some items
+     * cargoQueue.push({name: 'foo'}, function(err) {
+     *     console.log('finished processing foo');
+     * });
+     * cargoQueue.push({name: 'bar'}, function(err) {
+     *     console.log('finished processing bar');
+     * });
+     * cargoQueue.push({name: 'baz'}, function(err) {
+     *     console.log('finished processing baz');
+     * });
+     * cargoQueue.push({name: 'boo'}, function(err) {
+     *     console.log('finished processing boo');
+     * });
+     */
+    function cargo$1(worker, concurrency, payload) {
+        return queue(worker, concurrency, payload);
+    }
+
+    /**
+     * Reduces `coll` into a single value using an async `iteratee` to return each
+     * successive step. `memo` is the initial state of the reduction. This function
+     * only operates in series.
+     *
+     * For performance reasons, it may make sense to split a call to this function
+     * into a parallel map, and then use the normal `Array.prototype.reduce` on the
+     * results. This function is for situations where each step in the reduction
+     * needs to be async; if you can get the data before reducing it, then it's
+     * probably a good idea to do so.
+     *
+     * @name reduce
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias inject
+     * @alias foldl
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {*} memo - The initial state of the reduction.
+     * @param {AsyncFunction} iteratee - A function applied to each item in the
+     * array to produce the next step in the reduction.
+     * The `iteratee` should complete with the next state of the reduction.
+     * If the iteratee completes with an error, the reduction is stopped and the
+     * main `callback` is immediately called with the error.
+     * Invoked with (memo, item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Result is the reduced value. Invoked with
+     * (err, result).
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * // file1.txt is a file that is 1000 bytes in size
+     * // file2.txt is a file that is 2000 bytes in size
+     * // file3.txt is a file that is 3000 bytes in size
+     * // file4.txt does not exist
+     *
+     * const fileList = ['file1.txt','file2.txt','file3.txt'];
+     * const withMissingFileList = ['file1.txt','file2.txt','file3.txt', 'file4.txt'];
+     *
+     * // asynchronous function that computes the file size in bytes
+     * // file size is added to the memoized value, then returned
+     * function getFileSizeInBytes(memo, file, callback) {
+     *     fs.stat(file, function(err, stat) {
+     *         if (err) {
+     *             return callback(err);
+     *         }
+     *         callback(null, memo + stat.size);
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.reduce(fileList, 0, getFileSizeInBytes, function(err, result) {
+     *     if (err) {
+     *         console.log(err);
+     *     } else {
+     *         console.log(result);
+     *         // 6000
+     *         // which is the sum of the file sizes of the three files
+     *     }
+     * });
+     *
+     * // Error Handling
+     * async.reduce(withMissingFileList, 0, getFileSizeInBytes, function(err, result) {
+     *     if (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     } else {
+     *         console.log(result);
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.reduce(fileList, 0, getFileSizeInBytes)
+     * .then( result => {
+     *     console.log(result);
+     *     // 6000
+     *     // which is the sum of the file sizes of the three files
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Error Handling
+     * async.reduce(withMissingFileList, 0, getFileSizeInBytes)
+     * .then( result => {
+     *     console.log(result);
+     * }).catch( err => {
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.reduce(fileList, 0, getFileSizeInBytes);
+     *         console.log(result);
+     *         // 6000
+     *         // which is the sum of the file sizes of the three files
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // Error Handling
+     * async () => {
+     *     try {
+     *         let result = await async.reduce(withMissingFileList, 0, getFileSizeInBytes);
+     *         console.log(result);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     }
+     * }
+     *
+     */
+    function reduce(coll, memo, iteratee, callback) {
+        callback = once(callback);
+        var _iteratee = wrapAsync(iteratee);
+        return eachOfSeries$1(coll, (x, i, iterCb) => {
+            _iteratee(memo, x, (err, v) => {
+                memo = v;
+                iterCb(err);
+            });
+        }, err => callback(err, memo));
+    }
+    var reduce$1 = awaitify(reduce, 4);
+
+    /**
+     * Version of the compose function that is more natural to read. Each function
+     * consumes the return value of the previous function. It is the equivalent of
+     * [compose]{@link module:ControlFlow.compose} with the arguments reversed.
+     *
+     * Each function is executed with the `this` binding of the composed function.
+     *
+     * @name seq
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.compose]{@link module:ControlFlow.compose}
+     * @category Control Flow
+     * @param {...AsyncFunction} functions - the asynchronous functions to compose
+     * @returns {Function} a function that composes the `functions` in order
+     * @example
+     *
+     * // Requires lodash (or underscore), express3 and dresende's orm2.
+     * // Part of an app, that fetches cats of the logged user.
+     * // This example uses `seq` function to avoid overnesting and error
+     * // handling clutter.
+     * app.get('/cats', function(request, response) {
+     *     var User = request.models.User;
+     *     async.seq(
+     *         User.get.bind(User),  // 'User.get' has signature (id, callback(err, data))
+     *         function(user, fn) {
+     *             user.getCats(fn);      // 'getCats' has signature (callback(err, data))
+     *         }
+     *     )(req.session.user_id, function (err, cats) {
+     *         if (err) {
+     *             console.error(err);
+     *             response.json({ status: 'error', message: err.message });
+     *         } else {
+     *             response.json({ status: 'ok', message: 'Cats found', data: cats });
+     *         }
+     *     });
+     * });
+     */
+    function seq(...functions) {
+        var _functions = functions.map(wrapAsync);
+        return function (...args) {
+            var that = this;
+
+            var cb = args[args.length - 1];
+            if (typeof cb == 'function') {
+                args.pop();
+            } else {
+                cb = promiseCallback();
+            }
+
+            reduce$1(_functions, args, (newargs, fn, iterCb) => {
+                fn.apply(that, newargs.concat((err, ...nextargs) => {
+                    iterCb(err, nextargs);
+                }));
+            },
+            (err, results) => cb(err, ...results));
+
+            return cb[PROMISE_SYMBOL]
+        };
+    }
+
+    /**
+     * Creates a function which is a composition of the passed asynchronous
+     * functions. Each function consumes the return value of the function that
+     * follows. Composing functions `f()`, `g()`, and `h()` would produce the result
+     * of `f(g(h()))`, only this version uses callbacks to obtain the return values.
+     *
+     * If the last argument to the composed function is not a function, a promise
+     * is returned when you call it.
+     *
+     * Each function is executed with the `this` binding of the composed function.
+     *
+     * @name compose
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {...AsyncFunction} functions - the asynchronous functions to compose
+     * @returns {Function} an asynchronous function that is the composed
+     * asynchronous `functions`
+     * @example
+     *
+     * function add1(n, callback) {
+     *     setTimeout(function () {
+     *         callback(null, n + 1);
+     *     }, 10);
+     * }
+     *
+     * function mul3(n, callback) {
+     *     setTimeout(function () {
+     *         callback(null, n * 3);
+     *     }, 10);
+     * }
+     *
+     * var add1mul3 = async.compose(mul3, add1);
+     * add1mul3(4, function (err, result) {
+     *     // result now equals 15
+     * });
+     */
+    function compose(...args) {
+        return seq(...args.reverse());
+    }
+
+    /**
+     * The same as [`map`]{@link module:Collections.map} but runs a maximum of `limit` async operations at a time.
+     *
+     * @name mapLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.map]{@link module:Collections.map}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with the transformed item.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Results is an array of the
+     * transformed items from the `coll`. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function mapLimit (coll, limit, iteratee, callback) {
+        return _asyncMap(eachOfLimit(limit), coll, iteratee, callback)
+    }
+    var mapLimit$1 = awaitify(mapLimit, 4);
+
+    /**
+     * The same as [`concat`]{@link module:Collections.concat} but runs a maximum of `limit` async operations at a time.
+     *
+     * @name concatLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.concat]{@link module:Collections.concat}
+     * @category Collection
+     * @alias flatMapLimit
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`,
+     * which should use an array as its result. Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished, or an error occurs. Results is an array
+     * containing the concatenated results of the `iteratee` function. Invoked with
+     * (err, results).
+     * @returns A Promise, if no callback is passed
+     */
+    function concatLimit(coll, limit, iteratee, callback) {
+        var _iteratee = wrapAsync(iteratee);
+        return mapLimit$1(coll, limit, (val, iterCb) => {
+            _iteratee(val, (err, ...args) => {
+                if (err) return iterCb(err);
+                return iterCb(err, args);
+            });
+        }, (err, mapResults) => {
+            var result = [];
+            for (var i = 0; i < mapResults.length; i++) {
+                if (mapResults[i]) {
+                    result = result.concat(...mapResults[i]);
+                }
+            }
+
+            return callback(err, result);
+        });
+    }
+    var concatLimit$1 = awaitify(concatLimit, 4);
+
+    /**
+     * Applies `iteratee` to each item in `coll`, concatenating the results. Returns
+     * the concatenated list. The `iteratee`s are called in parallel, and the
+     * results are concatenated as they return. The results array will be returned in
+     * the original order of `coll` passed to the `iteratee` function.
+     *
+     * @name concat
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @category Collection
+     * @alias flatMap
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`,
+     * which should use an array as its result. Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished, or an error occurs. Results is an array
+     * containing the concatenated results of the `iteratee` function. Invoked with
+     * (err, results).
+     * @returns A Promise, if no callback is passed
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     * // dir4 does not exist
+     *
+     * let directoryList = ['dir1','dir2','dir3'];
+     * let withMissingDirectoryList = ['dir1','dir2','dir3', 'dir4'];
+     *
+     * // Using callbacks
+     * async.concat(directoryList, fs.readdir, function(err, results) {
+     *    if (err) {
+     *        console.log(err);
+     *    } else {
+     *        console.log(results);
+     *        // [ 'file1.txt', 'file2.txt', 'file3.txt', 'file4.txt', file5.txt ]
+     *    }
+     * });
+     *
+     * // Error Handling
+     * async.concat(withMissingDirectoryList, fs.readdir, function(err, results) {
+     *    if (err) {
+     *        console.log(err);
+     *        // [ Error: ENOENT: no such file or directory ]
+     *        // since dir4 does not exist
+     *    } else {
+     *        console.log(results);
+     *    }
+     * });
+     *
+     * // Using Promises
+     * async.concat(directoryList, fs.readdir)
+     * .then(results => {
+     *     console.log(results);
+     *     // [ 'file1.txt', 'file2.txt', 'file3.txt', 'file4.txt', file5.txt ]
+     * }).catch(err => {
+     *      console.log(err);
+     * });
+     *
+     * // Error Handling
+     * async.concat(withMissingDirectoryList, fs.readdir)
+     * .then(results => {
+     *     console.log(results);
+     * }).catch(err => {
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     *     // since dir4 does not exist
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.concat(directoryList, fs.readdir);
+     *         console.log(results);
+     *         // [ 'file1.txt', 'file2.txt', 'file3.txt', 'file4.txt', file5.txt ]
+     *     } catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // Error Handling
+     * async () => {
+     *     try {
+     *         let results = await async.concat(withMissingDirectoryList, fs.readdir);
+     *         console.log(results);
+     *     } catch (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *         // since dir4 does not exist
+     *     }
+     * }
+     *
+     */
+    function concat(coll, iteratee, callback) {
+        return concatLimit$1(coll, Infinity, iteratee, callback)
+    }
+    var concat$1 = awaitify(concat, 3);
+
+    /**
+     * The same as [`concat`]{@link module:Collections.concat} but runs only a single async operation at a time.
+     *
+     * @name concatSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.concat]{@link module:Collections.concat}
+     * @category Collection
+     * @alias flatMapSeries
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A function to apply to each item in `coll`.
+     * The iteratee should complete with an array an array of results.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished, or an error occurs. Results is an array
+     * containing the concatenated results of the `iteratee` function. Invoked with
+     * (err, results).
+     * @returns A Promise, if no callback is passed
+     */
+    function concatSeries(coll, iteratee, callback) {
+        return concatLimit$1(coll, 1, iteratee, callback)
+    }
+    var concatSeries$1 = awaitify(concatSeries, 3);
+
+    /**
+     * Returns a function that when called, calls-back with the values provided.
+     * Useful as the first function in a [`waterfall`]{@link module:ControlFlow.waterfall}, or for plugging values in to
+     * [`auto`]{@link module:ControlFlow.auto}.
+     *
+     * @name constant
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {...*} arguments... - Any number of arguments to automatically invoke
+     * callback with.
+     * @returns {AsyncFunction} Returns a function that when invoked, automatically
+     * invokes the callback with the previous given arguments.
+     * @example
+     *
+     * async.waterfall([
+     *     async.constant(42),
+     *     function (value, next) {
+     *         // value === 42
+     *     },
+     *     //...
+     * ], callback);
+     *
+     * async.waterfall([
+     *     async.constant(filename, "utf8"),
+     *     fs.readFile,
+     *     function (fileData, next) {
+     *         //...
+     *     }
+     *     //...
+     * ], callback);
+     *
+     * async.auto({
+     *     hostname: async.constant("https://server.net/"),
+     *     port: findFreePort,
+     *     launchServer: ["hostname", "port", function (options, cb) {
+     *         startServer(options, cb);
+     *     }],
+     *     //...
+     * }, callback);
+     */
+    function constant(...args) {
+        return function (...ignoredArgs/*, callback*/) {
+            var callback = ignoredArgs.pop();
+            return callback(null, ...args);
+        };
+    }
+
+    function _createTester(check, getResult) {
+        return (eachfn, arr, _iteratee, cb) => {
+            var testPassed = false;
+            var testResult;
+            const iteratee = wrapAsync(_iteratee);
+            eachfn(arr, (value, _, callback) => {
+                iteratee(value, (err, result) => {
+                    if (err || err === false) return callback(err);
+
+                    if (check(result) && !testResult) {
+                        testPassed = true;
+                        testResult = getResult(true, value);
+                        return callback(null, breakLoop);
+                    }
+                    callback();
+                });
+            }, err => {
+                if (err) return cb(err);
+                cb(null, testPassed ? testResult : getResult(false));
+            });
+        };
+    }
+
+    /**
+     * Returns the first value in `coll` that passes an async truth test. The
+     * `iteratee` is applied in parallel, meaning the first iteratee to return
+     * `true` will fire the detect `callback` with that result. That means the
+     * result might not be the first item in the original `coll` (in terms of order)
+     * that passes the test.
+
+     * If order within the original `coll` is important, then look at
+     * [`detectSeries`]{@link module:Collections.detectSeries}.
+     *
+     * @name detect
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias find
+     * @category Collections
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
+     * The iteratee must complete with a boolean value as its result.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called as soon as any
+     * iteratee returns `true`, or after all the `iteratee` functions have finished.
+     * Result will be the first item in the array that passes the truth test
+     * (iteratee) or the value `undefined` if none passed. Invoked with
+     * (err, result).
+     * @returns {Promise} a promise, if a callback is omitted
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     *
+     * // asynchronous function that checks if a file exists
+     * function fileExists(file, callback) {
+     *    fs.access(file, fs.constants.F_OK, (err) => {
+     *        callback(null, !err);
+     *    });
+     * }
+     *
+     * async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists,
+     *    function(err, result) {
+     *        console.log(result);
+     *        // dir1/file1.txt
+     *        // result now equals the first file in the list that exists
+     *    }
+     *);
+     *
+     * // Using Promises
+     * async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists)
+     * .then(result => {
+     *     console.log(result);
+     *     // dir1/file1.txt
+     *     // result now equals the first file in the list that exists
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.detect(['file3.txt','file2.txt','dir1/file1.txt'], fileExists);
+     *         console.log(result);
+     *         // dir1/file1.txt
+     *         // result now equals the file in the list that exists
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function detect(coll, iteratee, callback) {
+        return _createTester(bool => bool, (res, item) => item)(eachOf$1, coll, iteratee, callback)
+    }
+    var detect$1 = awaitify(detect, 3);
+
+    /**
+     * The same as [`detect`]{@link module:Collections.detect} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name detectLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.detect]{@link module:Collections.detect}
+     * @alias findLimit
+     * @category Collections
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
+     * The iteratee must complete with a boolean value as its result.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called as soon as any
+     * iteratee returns `true`, or after all the `iteratee` functions have finished.
+     * Result will be the first item in the array that passes the truth test
+     * (iteratee) or the value `undefined` if none passed. Invoked with
+     * (err, result).
+     * @returns {Promise} a promise, if a callback is omitted
+     */
+    function detectLimit(coll, limit, iteratee, callback) {
+        return _createTester(bool => bool, (res, item) => item)(eachOfLimit(limit), coll, iteratee, callback)
+    }
+    var detectLimit$1 = awaitify(detectLimit, 4);
+
+    /**
+     * The same as [`detect`]{@link module:Collections.detect} but runs only a single async operation at a time.
+     *
+     * @name detectSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.detect]{@link module:Collections.detect}
+     * @alias findSeries
+     * @category Collections
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A truth test to apply to each item in `coll`.
+     * The iteratee must complete with a boolean value as its result.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called as soon as any
+     * iteratee returns `true`, or after all the `iteratee` functions have finished.
+     * Result will be the first item in the array that passes the truth test
+     * (iteratee) or the value `undefined` if none passed. Invoked with
+     * (err, result).
+     * @returns {Promise} a promise, if a callback is omitted
+     */
+    function detectSeries(coll, iteratee, callback) {
+        return _createTester(bool => bool, (res, item) => item)(eachOfLimit(1), coll, iteratee, callback)
+    }
+
+    var detectSeries$1 = awaitify(detectSeries, 3);
+
+    function consoleFunc(name) {
+        return (fn, ...args) => wrapAsync(fn)(...args, (err, ...resultArgs) => {
+            /* istanbul ignore else */
+            if (typeof console === 'object') {
+                /* istanbul ignore else */
+                if (err) {
+                    /* istanbul ignore else */
+                    if (console.error) {
+                        console.error(err);
+                    }
+                } else if (console[name]) { /* istanbul ignore else */
+                    resultArgs.forEach(x => console[name](x));
+                }
+            }
+        })
+    }
+
+    /**
+     * Logs the result of an [`async` function]{@link AsyncFunction} to the
+     * `console` using `console.dir` to display the properties of the resulting object.
+     * Only works in Node.js or in browsers that support `console.dir` and
+     * `console.error` (such as FF and Chrome).
+     * If multiple arguments are returned from the async function,
+     * `console.dir` is called on each argument in order.
+     *
+     * @name dir
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {AsyncFunction} function - The function you want to eventually apply
+     * all arguments to.
+     * @param {...*} arguments... - Any number of arguments to apply to the function.
+     * @example
+     *
+     * // in a module
+     * var hello = function(name, callback) {
+     *     setTimeout(function() {
+     *         callback(null, {hello: name});
+     *     }, 1000);
+     * };
+     *
+     * // in the node repl
+     * node> async.dir(hello, 'world');
+     * {hello: 'world'}
+     */
+    var dir = consoleFunc('dir');
+
+    /**
+     * The post-check version of [`whilst`]{@link module:ControlFlow.whilst}. To reflect the difference in
+     * the order of operations, the arguments `test` and `iteratee` are switched.
+     *
+     * `doWhilst` is to `whilst` as `do while` is to `while` in plain JavaScript.
+     *
+     * @name doWhilst
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.whilst]{@link module:ControlFlow.whilst}
+     * @category Control Flow
+     * @param {AsyncFunction} iteratee - A function which is called each time `test`
+     * passes. Invoked with (callback).
+     * @param {AsyncFunction} test - asynchronous truth test to perform after each
+     * execution of `iteratee`. Invoked with (...args, callback), where `...args` are the
+     * non-error args from the previous callback of `iteratee`.
+     * @param {Function} [callback] - A callback which is called after the test
+     * function has failed and repeated execution of `iteratee` has stopped.
+     * `callback` will be passed an error and any arguments passed to the final
+     * `iteratee`'s callback. Invoked with (err, [results]);
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function doWhilst(iteratee, test, callback) {
+        callback = onlyOnce(callback);
+        var _fn = wrapAsync(iteratee);
+        var _test = wrapAsync(test);
+        var results;
+
+        function next(err, ...args) {
+            if (err) return callback(err);
+            if (err === false) return;
+            results = args;
+            _test(...args, check);
+        }
+
+        function check(err, truth) {
+            if (err) return callback(err);
+            if (err === false) return;
+            if (!truth) return callback(null, ...results);
+            _fn(next);
+        }
+
+        return check(null, true);
+    }
+
+    var doWhilst$1 = awaitify(doWhilst, 3);
+
+    /**
+     * Like ['doWhilst']{@link module:ControlFlow.doWhilst}, except the `test` is inverted. Note the
+     * argument ordering differs from `until`.
+     *
+     * @name doUntil
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.doWhilst]{@link module:ControlFlow.doWhilst}
+     * @category Control Flow
+     * @param {AsyncFunction} iteratee - An async function which is called each time
+     * `test` fails. Invoked with (callback).
+     * @param {AsyncFunction} test - asynchronous truth test to perform after each
+     * execution of `iteratee`. Invoked with (...args, callback), where `...args` are the
+     * non-error args from the previous callback of `iteratee`
+     * @param {Function} [callback] - A callback which is called after the test
+     * function has passed and repeated execution of `iteratee` has stopped. `callback`
+     * will be passed an error and any arguments passed to the final `iteratee`'s
+     * callback. Invoked with (err, [results]);
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function doUntil(iteratee, test, callback) {
+        const _test = wrapAsync(test);
+        return doWhilst$1(iteratee, (...args) => {
+            const cb = args.pop();
+            _test(...args, (err, truth) => cb (err, !truth));
+        }, callback);
+    }
+
+    function _withoutIndex(iteratee) {
+        return (value, index, callback) => iteratee(value, callback);
+    }
+
+    /**
+     * Applies the function `iteratee` to each item in `coll`, in parallel.
+     * The `iteratee` is called with an item from the list, and a callback for when
+     * it has finished. If the `iteratee` passes an error to its `callback`, the
+     * main `callback` (for the `each` function) is immediately called with the
+     * error.
+     *
+     * Note, that since this function applies `iteratee` to each item in parallel,
+     * there is no guarantee that the iteratee functions will complete in order.
+     *
+     * @name each
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias forEach
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to
+     * each item in `coll`. Invoked with (item, callback).
+     * The array index is not passed to the iteratee.
+     * If you need the index, use `eachOf`.
+     * @param {Function} [callback] - A callback which is called when all
+     * `iteratee` functions have finished, or an error occurs. Invoked with (err).
+     * @returns {Promise} a promise, if a callback is omitted
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     * // dir4 does not exist
+     *
+     * const fileList = [ 'dir1/file2.txt', 'dir2/file3.txt', 'dir/file5.txt'];
+     * const withMissingFileList = ['dir1/file1.txt', 'dir4/file2.txt'];
+     *
+     * // asynchronous function that deletes a file
+     * const deleteFile = function(file, callback) {
+     *     fs.unlink(file, callback);
+     * };
+     *
+     * // Using callbacks
+     * async.each(fileList, deleteFile, function(err) {
+     *     if( err ) {
+     *         console.log(err);
+     *     } else {
+     *         console.log('All files have been deleted successfully');
+     *     }
+     * });
+     *
+     * // Error Handling
+     * async.each(withMissingFileList, deleteFile, function(err){
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     *     // since dir4/file2.txt does not exist
+     *     // dir1/file1.txt could have been deleted
+     * });
+     *
+     * // Using Promises
+     * async.each(fileList, deleteFile)
+     * .then( () => {
+     *     console.log('All files have been deleted successfully');
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Error Handling
+     * async.each(fileList, deleteFile)
+     * .then( () => {
+     *     console.log('All files have been deleted successfully');
+     * }).catch( err => {
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     *     // since dir4/file2.txt does not exist
+     *     // dir1/file1.txt could have been deleted
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         await async.each(files, deleteFile);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // Error Handling
+     * async () => {
+     *     try {
+     *         await async.each(withMissingFileList, deleteFile);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *         // since dir4/file2.txt does not exist
+     *         // dir1/file1.txt could have been deleted
+     *     }
+     * }
+     *
+     */
+    function eachLimit(coll, iteratee, callback) {
+        return eachOf$1(coll, _withoutIndex(wrapAsync(iteratee)), callback);
+    }
+
+    var each = awaitify(eachLimit, 3);
+
+    /**
+     * The same as [`each`]{@link module:Collections.each} but runs a maximum of `limit` async operations at a time.
+     *
+     * @name eachLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.each]{@link module:Collections.each}
+     * @alias forEachLimit
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The array index is not passed to the iteratee.
+     * If you need the index, use `eachOfLimit`.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called when all
+     * `iteratee` functions have finished, or an error occurs. Invoked with (err).
+     * @returns {Promise} a promise, if a callback is omitted
+     */
+    function eachLimit$1(coll, limit, iteratee, callback) {
+        return eachOfLimit(limit)(coll, _withoutIndex(wrapAsync(iteratee)), callback);
+    }
+    var eachLimit$2 = awaitify(eachLimit$1, 4);
+
+    /**
+     * The same as [`each`]{@link module:Collections.each} but runs only a single async operation at a time.
+     *
+     * Note, that unlike [`each`]{@link module:Collections.each}, this function applies iteratee to each item
+     * in series and therefore the iteratee functions will complete in order.
+
+     * @name eachSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.each]{@link module:Collections.each}
+     * @alias forEachSeries
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each
+     * item in `coll`.
+     * The array index is not passed to the iteratee.
+     * If you need the index, use `eachOfSeries`.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called when all
+     * `iteratee` functions have finished, or an error occurs. Invoked with (err).
+     * @returns {Promise} a promise, if a callback is omitted
+     */
+    function eachSeries(coll, iteratee, callback) {
+        return eachLimit$2(coll, 1, iteratee, callback)
+    }
+    var eachSeries$1 = awaitify(eachSeries, 3);
+
+    /**
+     * Wrap an async function and ensure it calls its callback on a later tick of
+     * the event loop.  If the function already calls its callback on a next tick,
+     * no extra deferral is added. This is useful for preventing stack overflows
+     * (`RangeError: Maximum call stack size exceeded`) and generally keeping
+     * [Zalgo](http://blog.izs.me/post/59142742143/designing-apis-for-asynchrony)
+     * contained. ES2017 `async` functions are returned as-is -- they are immune
+     * to Zalgo's corrupting influences, as they always resolve on a later tick.
+     *
+     * @name ensureAsync
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {AsyncFunction} fn - an async function, one that expects a node-style
+     * callback as its last argument.
+     * @returns {AsyncFunction} Returns a wrapped function with the exact same call
+     * signature as the function passed in.
+     * @example
+     *
+     * function sometimesAsync(arg, callback) {
+     *     if (cache[arg]) {
+     *         return callback(null, cache[arg]); // this would be synchronous!!
+     *     } else {
+     *         doSomeIO(arg, callback); // this IO would be asynchronous
+     *     }
+     * }
+     *
+     * // this has a risk of stack overflows if many results are cached in a row
+     * async.mapSeries(args, sometimesAsync, done);
+     *
+     * // this will defer sometimesAsync's callback if necessary,
+     * // preventing stack overflows
+     * async.mapSeries(args, async.ensureAsync(sometimesAsync), done);
+     */
+    function ensureAsync(fn) {
+        if (isAsync(fn)) return fn;
+        return function (...args/*, callback*/) {
+            var callback = args.pop();
+            var sync = true;
+            args.push((...innerArgs) => {
+                if (sync) {
+                    setImmediate$1(() => callback(...innerArgs));
+                } else {
+                    callback(...innerArgs);
+                }
+            });
+            fn.apply(this, args);
+            sync = false;
+        };
+    }
+
+    /**
+     * Returns `true` if every element in `coll` satisfies an async test. If any
+     * iteratee call returns `false`, the main `callback` is immediately called.
+     *
+     * @name every
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias all
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async truth test to apply to each item
+     * in the collection in parallel.
+     * The iteratee must complete with a boolean result value.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Result will be either `true` or `false`
+     * depending on the values of the async tests. Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     * // dir4 does not exist
+     *
+     * const fileList = ['dir1/file1.txt','dir2/file3.txt','dir3/file5.txt'];
+     * const withMissingFileList = ['file1.txt','file2.txt','file4.txt'];
+     *
+     * // asynchronous function that checks if a file exists
+     * function fileExists(file, callback) {
+     *    fs.access(file, fs.constants.F_OK, (err) => {
+     *        callback(null, !err);
+     *    });
+     * }
+     *
+     * // Using callbacks
+     * async.every(fileList, fileExists, function(err, result) {
+     *     console.log(result);
+     *     // true
+     *     // result is true since every file exists
+     * });
+     *
+     * async.every(withMissingFileList, fileExists, function(err, result) {
+     *     console.log(result);
+     *     // false
+     *     // result is false since NOT every file exists
+     * });
+     *
+     * // Using Promises
+     * async.every(fileList, fileExists)
+     * .then( result => {
+     *     console.log(result);
+     *     // true
+     *     // result is true since every file exists
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * async.every(withMissingFileList, fileExists)
+     * .then( result => {
+     *     console.log(result);
+     *     // false
+     *     // result is false since NOT every file exists
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.every(fileList, fileExists);
+     *         console.log(result);
+     *         // true
+     *         // result is true since every file exists
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * async () => {
+     *     try {
+     *         let result = await async.every(withMissingFileList, fileExists);
+     *         console.log(result);
+     *         // false
+     *         // result is false since NOT every file exists
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function every(coll, iteratee, callback) {
+        return _createTester(bool => !bool, res => !res)(eachOf$1, coll, iteratee, callback)
+    }
+    var every$1 = awaitify(every, 3);
+
+    /**
+     * The same as [`every`]{@link module:Collections.every} but runs a maximum of `limit` async operations at a time.
+     *
+     * @name everyLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.every]{@link module:Collections.every}
+     * @alias allLimit
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - An async truth test to apply to each item
+     * in the collection in parallel.
+     * The iteratee must complete with a boolean result value.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Result will be either `true` or `false`
+     * depending on the values of the async tests. Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     */
+    function everyLimit(coll, limit, iteratee, callback) {
+        return _createTester(bool => !bool, res => !res)(eachOfLimit(limit), coll, iteratee, callback)
+    }
+    var everyLimit$1 = awaitify(everyLimit, 4);
+
+    /**
+     * The same as [`every`]{@link module:Collections.every} but runs only a single async operation at a time.
+     *
+     * @name everySeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.every]{@link module:Collections.every}
+     * @alias allSeries
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async truth test to apply to each item
+     * in the collection in series.
+     * The iteratee must complete with a boolean result value.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Result will be either `true` or `false`
+     * depending on the values of the async tests. Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     */
+    function everySeries(coll, iteratee, callback) {
+        return _createTester(bool => !bool, res => !res)(eachOfSeries$1, coll, iteratee, callback)
+    }
+    var everySeries$1 = awaitify(everySeries, 3);
+
+    function filterArray(eachfn, arr, iteratee, callback) {
+        var truthValues = new Array(arr.length);
+        eachfn(arr, (x, index, iterCb) => {
+            iteratee(x, (err, v) => {
+                truthValues[index] = !!v;
+                iterCb(err);
+            });
+        }, err => {
+            if (err) return callback(err);
+            var results = [];
+            for (var i = 0; i < arr.length; i++) {
+                if (truthValues[i]) results.push(arr[i]);
+            }
+            callback(null, results);
+        });
+    }
+
+    function filterGeneric(eachfn, coll, iteratee, callback) {
+        var results = [];
+        eachfn(coll, (x, index, iterCb) => {
+            iteratee(x, (err, v) => {
+                if (err) return iterCb(err);
+                if (v) {
+                    results.push({index, value: x});
+                }
+                iterCb(err);
+            });
+        }, err => {
+            if (err) return callback(err);
+            callback(null, results
+                .sort((a, b) => a.index - b.index)
+                .map(v => v.value));
+        });
+    }
+
+    function _filter(eachfn, coll, iteratee, callback) {
+        var filter = isArrayLike(coll) ? filterArray : filterGeneric;
+        return filter(eachfn, coll, wrapAsync(iteratee), callback);
+    }
+
+    /**
+     * Returns a new array of all the values in `coll` which pass an async truth
+     * test. This operation is performed in parallel, but the results array will be
+     * in the same order as the original.
+     *
+     * @name filter
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias select
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {Function} iteratee - A truth test to apply to each item in `coll`.
+     * The `iteratee` is passed a `callback(err, truthValue)`, which must be called
+     * with a boolean argument once it has completed. Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback provided
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     *
+     * const files = ['dir1/file1.txt','dir2/file3.txt','dir3/file6.txt'];
+     *
+     * // asynchronous function that checks if a file exists
+     * function fileExists(file, callback) {
+     *    fs.access(file, fs.constants.F_OK, (err) => {
+     *        callback(null, !err);
+     *    });
+     * }
+     *
+     * // Using callbacks
+     * async.filter(files, fileExists, function(err, results) {
+     *    if(err) {
+     *        console.log(err);
+     *    } else {
+     *        console.log(results);
+     *        // [ 'dir1/file1.txt', 'dir2/file3.txt' ]
+     *        // results is now an array of the existing files
+     *    }
+     * });
+     *
+     * // Using Promises
+     * async.filter(files, fileExists)
+     * .then(results => {
+     *     console.log(results);
+     *     // [ 'dir1/file1.txt', 'dir2/file3.txt' ]
+     *     // results is now an array of the existing files
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.filter(files, fileExists);
+     *         console.log(results);
+     *         // [ 'dir1/file1.txt', 'dir2/file3.txt' ]
+     *         // results is now an array of the existing files
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function filter (coll, iteratee, callback) {
+        return _filter(eachOf$1, coll, iteratee, callback)
+    }
+    var filter$1 = awaitify(filter, 3);
+
+    /**
+     * The same as [`filter`]{@link module:Collections.filter} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name filterLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.filter]{@link module:Collections.filter}
+     * @alias selectLimit
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {Function} iteratee - A truth test to apply to each item in `coll`.
+     * The `iteratee` is passed a `callback(err, truthValue)`, which must be called
+     * with a boolean argument once it has completed. Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback provided
+     */
+    function filterLimit (coll, limit, iteratee, callback) {
+        return _filter(eachOfLimit(limit), coll, iteratee, callback)
+    }
+    var filterLimit$1 = awaitify(filterLimit, 4);
+
+    /**
+     * The same as [`filter`]{@link module:Collections.filter} but runs only a single async operation at a time.
+     *
+     * @name filterSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.filter]{@link module:Collections.filter}
+     * @alias selectSeries
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {Function} iteratee - A truth test to apply to each item in `coll`.
+     * The `iteratee` is passed a `callback(err, truthValue)`, which must be called
+     * with a boolean argument once it has completed. Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Invoked with (err, results)
+     * @returns {Promise} a promise, if no callback provided
+     */
+    function filterSeries (coll, iteratee, callback) {
+        return _filter(eachOfSeries$1, coll, iteratee, callback)
+    }
+    var filterSeries$1 = awaitify(filterSeries, 3);
+
+    /**
+     * Calls the asynchronous function `fn` with a callback parameter that allows it
+     * to call itself again, in series, indefinitely.
+
+     * If an error is passed to the callback then `errback` is called with the
+     * error, and execution stops, otherwise it will never be called.
+     *
+     * @name forever
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {AsyncFunction} fn - an async function to call repeatedly.
+     * Invoked with (next).
+     * @param {Function} [errback] - when `fn` passes an error to it's callback,
+     * this function will be called, and execution stops. Invoked with (err).
+     * @returns {Promise} a promise that rejects if an error occurs and an errback
+     * is not passed
+     * @example
+     *
+     * async.forever(
+     *     function(next) {
+     *         // next is suitable for passing to things that need a callback(err [, whatever]);
+     *         // it will result in this function being called again.
+     *     },
+     *     function(err) {
+     *         // if next is called with a value in its first parameter, it will appear
+     *         // in here as 'err', and execution will stop.
+     *     }
+     * );
+     */
+    function forever(fn, errback) {
+        var done = onlyOnce(errback);
+        var task = wrapAsync(ensureAsync(fn));
+
+        function next(err) {
+            if (err) return done(err);
+            if (err === false) return;
+            task(next);
+        }
+        return next();
+    }
+    var forever$1 = awaitify(forever, 2);
+
+    /**
+     * The same as [`groupBy`]{@link module:Collections.groupBy} but runs a maximum of `limit` async operations at a time.
+     *
+     * @name groupByLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.groupBy]{@link module:Collections.groupBy}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with a `key` to group the value under.
+     * Invoked with (value, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Result is an `Object` whoses
+     * properties are arrays of values which returned the corresponding key.
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function groupByLimit(coll, limit, iteratee, callback) {
+        var _iteratee = wrapAsync(iteratee);
+        return mapLimit$1(coll, limit, (val, iterCb) => {
+            _iteratee(val, (err, key) => {
+                if (err) return iterCb(err);
+                return iterCb(err, {key, val});
+            });
+        }, (err, mapResults) => {
+            var result = {};
+            // from MDN, handle object having an `hasOwnProperty` prop
+            var {hasOwnProperty} = Object.prototype;
+
+            for (var i = 0; i < mapResults.length; i++) {
+                if (mapResults[i]) {
+                    var {key} = mapResults[i];
+                    var {val} = mapResults[i];
+
+                    if (hasOwnProperty.call(result, key)) {
+                        result[key].push(val);
+                    } else {
+                        result[key] = [val];
+                    }
+                }
+            }
+
+            return callback(err, result);
+        });
+    }
+
+    var groupByLimit$1 = awaitify(groupByLimit, 4);
+
+    /**
+     * Returns a new object, where each value corresponds to an array of items, from
+     * `coll`, that returned the corresponding key. That is, the keys of the object
+     * correspond to the values passed to the `iteratee` callback.
+     *
+     * Note: Since this function applies the `iteratee` to each item in parallel,
+     * there is no guarantee that the `iteratee` functions will complete in order.
+     * However, the values for each key in the `result` will be in the same order as
+     * the original `coll`. For Objects, the values will roughly be in the order of
+     * the original Objects' keys (but this can vary across JavaScript engines).
+     *
+     * @name groupBy
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with a `key` to group the value under.
+     * Invoked with (value, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Result is an `Object` whoses
+     * properties are arrays of values which returned the corresponding key.
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     * // dir4 does not exist
+     *
+     * const files = ['dir1/file1.txt','dir2','dir4']
+     *
+     * // asynchronous function that detects file type as none, file, or directory
+     * function detectFile(file, callback) {
+     *     fs.stat(file, function(err, stat) {
+     *         if (err) {
+     *             return callback(null, 'none');
+     *         }
+     *         callback(null, stat.isDirectory() ? 'directory' : 'file');
+     *     });
+     * }
+     *
+     * //Using callbacks
+     * async.groupBy(files, detectFile, function(err, result) {
+     *     if(err) {
+     *         console.log(err);
+     *     } else {
+     *	       console.log(result);
+     *         // {
+     *         //     file: [ 'dir1/file1.txt' ],
+     *         //     none: [ 'dir4' ],
+     *         //     directory: [ 'dir2']
+     *         // }
+     *         // result is object containing the files grouped by type
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.groupBy(files, detectFile)
+     * .then( result => {
+     *     console.log(result);
+     *     // {
+     *     //     file: [ 'dir1/file1.txt' ],
+     *     //     none: [ 'dir4' ],
+     *     //     directory: [ 'dir2']
+     *     // }
+     *     // result is object containing the files grouped by type
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.groupBy(files, detectFile);
+     *         console.log(result);
+     *         // {
+     *         //     file: [ 'dir1/file1.txt' ],
+     *         //     none: [ 'dir4' ],
+     *         //     directory: [ 'dir2']
+     *         // }
+     *         // result is object containing the files grouped by type
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function groupBy (coll, iteratee, callback) {
+        return groupByLimit$1(coll, Infinity, iteratee, callback)
+    }
+
+    /**
+     * The same as [`groupBy`]{@link module:Collections.groupBy} but runs only a single async operation at a time.
+     *
+     * @name groupBySeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.groupBy]{@link module:Collections.groupBy}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with a `key` to group the value under.
+     * Invoked with (value, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. Result is an `Object` whose
+     * properties are arrays of values which returned the corresponding key.
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function groupBySeries (coll, iteratee, callback) {
+        return groupByLimit$1(coll, 1, iteratee, callback)
+    }
+
+    /**
+     * Logs the result of an `async` function to the `console`. Only works in
+     * Node.js or in browsers that support `console.log` and `console.error` (such
+     * as FF and Chrome). If multiple arguments are returned from the async
+     * function, `console.log` is called on each argument in order.
+     *
+     * @name log
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {AsyncFunction} function - The function you want to eventually apply
+     * all arguments to.
+     * @param {...*} arguments... - Any number of arguments to apply to the function.
+     * @example
+     *
+     * // in a module
+     * var hello = function(name, callback) {
+     *     setTimeout(function() {
+     *         callback(null, 'hello ' + name);
+     *     }, 1000);
+     * };
+     *
+     * // in the node repl
+     * node> async.log(hello, 'world');
+     * 'hello world'
+     */
+    var log = consoleFunc('log');
+
+    /**
+     * The same as [`mapValues`]{@link module:Collections.mapValues} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name mapValuesLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.mapValues]{@link module:Collections.mapValues}
+     * @category Collection
+     * @param {Object} obj - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - A function to apply to each value and key
+     * in `coll`.
+     * The iteratee should complete with the transformed value as its result.
+     * Invoked with (value, key, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. `result` is a new object consisting
+     * of each key from `obj`, with each transformed value on the right-hand side.
+     * Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function mapValuesLimit(obj, limit, iteratee, callback) {
+        callback = once(callback);
+        var newObj = {};
+        var _iteratee = wrapAsync(iteratee);
+        return eachOfLimit(limit)(obj, (val, key, next) => {
+            _iteratee(val, key, (err, result) => {
+                if (err) return next(err);
+                newObj[key] = result;
+                next(err);
+            });
+        }, err => callback(err, newObj));
+    }
+
+    var mapValuesLimit$1 = awaitify(mapValuesLimit, 4);
+
+    /**
+     * A relative of [`map`]{@link module:Collections.map}, designed for use with objects.
+     *
+     * Produces a new Object by mapping each value of `obj` through the `iteratee`
+     * function. The `iteratee` is called each `value` and `key` from `obj` and a
+     * callback for when it has finished processing. Each of these callbacks takes
+     * two arguments: an `error`, and the transformed item from `obj`. If `iteratee`
+     * passes an error to its callback, the main `callback` (for the `mapValues`
+     * function) is immediately called with the error.
+     *
+     * Note, the order of the keys in the result is not guaranteed.  The keys will
+     * be roughly in the order they complete, (but this is very engine-specific)
+     *
+     * @name mapValues
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @category Collection
+     * @param {Object} obj - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A function to apply to each value and key
+     * in `coll`.
+     * The iteratee should complete with the transformed value as its result.
+     * Invoked with (value, key, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. `result` is a new object consisting
+     * of each key from `obj`, with each transformed value on the right-hand side.
+     * Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * // file1.txt is a file that is 1000 bytes in size
+     * // file2.txt is a file that is 2000 bytes in size
+     * // file3.txt is a file that is 3000 bytes in size
+     * // file4.txt does not exist
+     *
+     * const fileMap = {
+     *     f1: 'file1.txt',
+     *     f2: 'file2.txt',
+     *     f3: 'file3.txt'
+     * };
+     *
+     * const withMissingFileMap = {
+     *     f1: 'file1.txt',
+     *     f2: 'file2.txt',
+     *     f3: 'file4.txt'
+     * };
+     *
+     * // asynchronous function that returns the file size in bytes
+     * function getFileSizeInBytes(file, key, callback) {
+     *     fs.stat(file, function(err, stat) {
+     *         if (err) {
+     *             return callback(err);
+     *         }
+     *         callback(null, stat.size);
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.mapValues(fileMap, getFileSizeInBytes, function(err, result) {
+     *     if (err) {
+     *         console.log(err);
+     *     } else {
+     *         console.log(result);
+     *         // result is now a map of file size in bytes for each file, e.g.
+     *         // {
+     *         //     f1: 1000,
+     *         //     f2: 2000,
+     *         //     f3: 3000
+     *         // }
+     *     }
+     * });
+     *
+     * // Error handling
+     * async.mapValues(withMissingFileMap, getFileSizeInBytes, function(err, result) {
+     *     if (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     } else {
+     *         console.log(result);
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.mapValues(fileMap, getFileSizeInBytes)
+     * .then( result => {
+     *     console.log(result);
+     *     // result is now a map of file size in bytes for each file, e.g.
+     *     // {
+     *     //     f1: 1000,
+     *     //     f2: 2000,
+     *     //     f3: 3000
+     *     // }
+     * }).catch (err => {
+     *     console.log(err);
+     * });
+     *
+     * // Error Handling
+     * async.mapValues(withMissingFileMap, getFileSizeInBytes)
+     * .then( result => {
+     *     console.log(result);
+     * }).catch (err => {
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.mapValues(fileMap, getFileSizeInBytes);
+     *         console.log(result);
+     *         // result is now a map of file size in bytes for each file, e.g.
+     *         // {
+     *         //     f1: 1000,
+     *         //     f2: 2000,
+     *         //     f3: 3000
+     *         // }
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // Error Handling
+     * async () => {
+     *     try {
+     *         let result = await async.mapValues(withMissingFileMap, getFileSizeInBytes);
+     *         console.log(result);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     }
+     * }
+     *
+     */
+    function mapValues(obj, iteratee, callback) {
+        return mapValuesLimit$1(obj, Infinity, iteratee, callback)
+    }
+
+    /**
+     * The same as [`mapValues`]{@link module:Collections.mapValues} but runs only a single async operation at a time.
+     *
+     * @name mapValuesSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.mapValues]{@link module:Collections.mapValues}
+     * @category Collection
+     * @param {Object} obj - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - A function to apply to each value and key
+     * in `coll`.
+     * The iteratee should complete with the transformed value as its result.
+     * Invoked with (value, key, callback).
+     * @param {Function} [callback] - A callback which is called when all `iteratee`
+     * functions have finished, or an error occurs. `result` is a new object consisting
+     * of each key from `obj`, with each transformed value on the right-hand side.
+     * Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function mapValuesSeries(obj, iteratee, callback) {
+        return mapValuesLimit$1(obj, 1, iteratee, callback)
+    }
+
+    /**
+     * Caches the results of an async function. When creating a hash to store
+     * function results against, the callback is omitted from the hash and an
+     * optional hash function can be used.
+     *
+     * **Note: if the async function errs, the result will not be cached and
+     * subsequent calls will call the wrapped function.**
+     *
+     * If no hash function is specified, the first argument is used as a hash key,
+     * which may work reasonably if it is a string or a data type that converts to a
+     * distinct string. Note that objects and arrays will not behave reasonably.
+     * Neither will cases where the other arguments are significant. In such cases,
+     * specify your own hash function.
+     *
+     * The cache of results is exposed as the `memo` property of the function
+     * returned by `memoize`.
+     *
+     * @name memoize
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {AsyncFunction} fn - The async function to proxy and cache results from.
+     * @param {Function} hasher - An optional function for generating a custom hash
+     * for storing results. It has all the arguments applied to it apart from the
+     * callback, and must be synchronous.
+     * @returns {AsyncFunction} a memoized version of `fn`
+     * @example
+     *
+     * var slow_fn = function(name, callback) {
+     *     // do something
+     *     callback(null, result);
+     * };
+     * var fn = async.memoize(slow_fn);
+     *
+     * // fn can now be used as if it were slow_fn
+     * fn('some name', function() {
+     *     // callback
+     * });
+     */
+    function memoize(fn, hasher = v => v) {
+        var memo = Object.create(null);
+        var queues = Object.create(null);
+        var _fn = wrapAsync(fn);
+        var memoized = initialParams((args, callback) => {
+            var key = hasher(...args);
+            if (key in memo) {
+                setImmediate$1(() => callback(null, ...memo[key]));
+            } else if (key in queues) {
+                queues[key].push(callback);
+            } else {
+                queues[key] = [callback];
+                _fn(...args, (err, ...resultArgs) => {
+                    // #1465 don't memoize if an error occurred
+                    if (!err) {
+                        memo[key] = resultArgs;
+                    }
+                    var q = queues[key];
+                    delete queues[key];
+                    for (var i = 0, l = q.length; i < l; i++) {
+                        q[i](err, ...resultArgs);
+                    }
+                });
+            }
+        });
+        memoized.memo = memo;
+        memoized.unmemoized = fn;
+        return memoized;
+    }
+
+    /* istanbul ignore file */
+
+    /**
+     * Calls `callback` on a later loop around the event loop. In Node.js this just
+     * calls `process.nextTick`.  In the browser it will use `setImmediate` if
+     * available, otherwise `setTimeout(callback, 0)`, which means other higher
+     * priority events may precede the execution of `callback`.
+     *
+     * This is used internally for browser-compatibility purposes.
+     *
+     * @name nextTick
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @see [async.setImmediate]{@link module:Utils.setImmediate}
+     * @category Util
+     * @param {Function} callback - The function to call on a later loop around
+     * the event loop. Invoked with (args...).
+     * @param {...*} args... - any number of additional arguments to pass to the
+     * callback on the next tick.
+     * @example
+     *
+     * var call_order = [];
+     * async.nextTick(function() {
+     *     call_order.push('two');
+     *     // call_order now equals ['one','two']
+     * });
+     * call_order.push('one');
+     *
+     * async.setImmediate(function (a, b, c) {
+     *     // a, b, and c equal 1, 2, and 3
+     * }, 1, 2, 3);
+     */
+    var _defer$1;
+
+    if (hasNextTick) {
+        _defer$1 = process.nextTick;
+    } else if (hasSetImmediate) {
+        _defer$1 = setImmediate;
+    } else {
+        _defer$1 = fallback;
+    }
+
+    var nextTick = wrap(_defer$1);
+
+    var parallel = awaitify((eachfn, tasks, callback) => {
+        var results = isArrayLike(tasks) ? [] : {};
+
+        eachfn(tasks, (task, key, taskCb) => {
+            wrapAsync(task)((err, ...result) => {
+                if (result.length < 2) {
+                    [result] = result;
+                }
+                results[key] = result;
+                taskCb(err);
+            });
+        }, err => callback(err, results));
+    }, 3);
+
+    /**
+     * Run the `tasks` collection of functions in parallel, without waiting until
+     * the previous function has completed. If any of the functions pass an error to
+     * its callback, the main `callback` is immediately called with the value of the
+     * error. Once the `tasks` have completed, the results are passed to the final
+     * `callback` as an array.
+     *
+     * **Note:** `parallel` is about kicking-off I/O tasks in parallel, not about
+     * parallel execution of code.  If your tasks do not use any timers or perform
+     * any I/O, they will actually be executed in series.  Any synchronous setup
+     * sections for each task will happen one after the other.  JavaScript remains
+     * single-threaded.
+     *
+     * **Hint:** Use [`reflect`]{@link module:Utils.reflect} to continue the
+     * execution of other tasks when a task fails.
+     *
+     * It is also possible to use an object instead of an array. Each property will
+     * be run as a function and the results will be passed to the final `callback`
+     * as an object instead of an array. This can be a more readable way of handling
+     * results from {@link async.parallel}.
+     *
+     * @name parallel
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection of
+     * [async functions]{@link AsyncFunction} to run.
+     * Each async function can complete with any number of optional `result` values.
+     * @param {Function} [callback] - An optional callback to run once all the
+     * functions have completed successfully. This function gets a results array
+     * (or object) containing all the result arguments passed to the task callbacks.
+     * Invoked with (err, results).
+     * @returns {Promise} a promise, if a callback is not passed
+     *
+     * @example
+     *
+     * //Using Callbacks
+     * async.parallel([
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'two');
+     *         }, 100);
+     *     }
+     * ], function(err, results) {
+     *     console.log(results);
+     *     // results is equal to ['one','two'] even though
+     *     // the second function had a shorter timeout.
+     * });
+     *
+     * // an example using an object instead of an array
+     * async.parallel({
+     *     one: function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 1);
+     *         }, 200);
+     *     },
+     *     two: function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 2);
+     *         }, 100);
+     *     }
+     * }, function(err, results) {
+     *     console.log(results);
+     *     // results is equal to: { one: 1, two: 2 }
+     * });
+     *
+     * //Using Promises
+     * async.parallel([
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'two');
+     *         }, 100);
+     *     }
+     * ]).then(results => {
+     *     console.log(results);
+     *     // results is equal to ['one','two'] even though
+     *     // the second function had a shorter timeout.
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * // an example using an object instead of an array
+     * async.parallel({
+     *     one: function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 1);
+     *         }, 200);
+     *     },
+     *     two: function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 2);
+     *         }, 100);
+     *     }
+     * }).then(results => {
+     *     console.log(results);
+     *     // results is equal to: { one: 1, two: 2 }
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * //Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.parallel([
+     *             function(callback) {
+     *                 setTimeout(function() {
+     *                     callback(null, 'one');
+     *                 }, 200);
+     *             },
+     *             function(callback) {
+     *                 setTimeout(function() {
+     *                     callback(null, 'two');
+     *                 }, 100);
+     *             }
+     *         ]);
+     *         console.log(results);
+     *         // results is equal to ['one','two'] even though
+     *         // the second function had a shorter timeout.
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // an example using an object instead of an array
+     * async () => {
+     *     try {
+     *         let results = await async.parallel({
+     *             one: function(callback) {
+     *                 setTimeout(function() {
+     *                     callback(null, 1);
+     *                 }, 200);
+     *             },
+     *            two: function(callback) {
+     *                 setTimeout(function() {
+     *                     callback(null, 2);
+     *                 }, 100);
+     *            }
+     *         });
+     *         console.log(results);
+     *         // results is equal to: { one: 1, two: 2 }
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function parallel$1(tasks, callback) {
+        return parallel(eachOf$1, tasks, callback);
+    }
+
+    /**
+     * The same as [`parallel`]{@link module:ControlFlow.parallel} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name parallelLimit
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.parallel]{@link module:ControlFlow.parallel}
+     * @category Control Flow
+     * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection of
+     * [async functions]{@link AsyncFunction} to run.
+     * Each async function can complete with any number of optional `result` values.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {Function} [callback] - An optional callback to run once all the
+     * functions have completed successfully. This function gets a results array
+     * (or object) containing all the result arguments passed to the task callbacks.
+     * Invoked with (err, results).
+     * @returns {Promise} a promise, if a callback is not passed
+     */
+    function parallelLimit(tasks, limit, callback) {
+        return parallel(eachOfLimit(limit), tasks, callback);
+    }
+
+    /**
+     * A queue of tasks for the worker function to complete.
+     * @typedef {Iterable} QueueObject
+     * @memberOf module:ControlFlow
+     * @property {Function} length - a function returning the number of items
+     * waiting to be processed. Invoke with `queue.length()`.
+     * @property {boolean} started - a boolean indicating whether or not any
+     * items have been pushed and processed by the queue.
+     * @property {Function} running - a function returning the number of items
+     * currently being processed. Invoke with `queue.running()`.
+     * @property {Function} workersList - a function returning the array of items
+     * currently being processed. Invoke with `queue.workersList()`.
+     * @property {Function} idle - a function returning false if there are items
+     * waiting or being processed, or true if not. Invoke with `queue.idle()`.
+     * @property {number} concurrency - an integer for determining how many `worker`
+     * functions should be run in parallel. This property can be changed after a
+     * `queue` is created to alter the concurrency on-the-fly.
+     * @property {number} payload - an integer that specifies how many items are
+     * passed to the worker function at a time. only applies if this is a
+     * [cargo]{@link module:ControlFlow.cargo} object
+     * @property {AsyncFunction} push - add a new task to the `queue`. Calls `callback`
+     * once the `worker` has finished processing the task. Instead of a single task,
+     * a `tasks` array can be submitted. The respective callback is used for every
+     * task in the list. Invoke with `queue.push(task, [callback])`,
+     * @property {AsyncFunction} unshift - add a new task to the front of the `queue`.
+     * Invoke with `queue.unshift(task, [callback])`.
+     * @property {AsyncFunction} pushAsync - the same as `q.push`, except this returns
+     * a promise that rejects if an error occurs.
+     * @property {AsyncFunction} unshiftAsync - the same as `q.unshift`, except this returns
+     * a promise that rejects if an error occurs.
+     * @property {Function} remove - remove items from the queue that match a test
+     * function.  The test function will be passed an object with a `data` property,
+     * and a `priority` property, if this is a
+     * [priorityQueue]{@link module:ControlFlow.priorityQueue} object.
+     * Invoked with `queue.remove(testFn)`, where `testFn` is of the form
+     * `function ({data, priority}) {}` and returns a Boolean.
+     * @property {Function} saturated - a function that sets a callback that is
+     * called when the number of running workers hits the `concurrency` limit, and
+     * further tasks will be queued.  If the callback is omitted, `q.saturated()`
+     * returns a promise for the next occurrence.
+     * @property {Function} unsaturated - a function that sets a callback that is
+     * called when the number of running workers is less than the `concurrency` &
+     * `buffer` limits, and further tasks will not be queued. If the callback is
+     * omitted, `q.unsaturated()` returns a promise for the next occurrence.
+     * @property {number} buffer - A minimum threshold buffer in order to say that
+     * the `queue` is `unsaturated`.
+     * @property {Function} empty - a function that sets a callback that is called
+     * when the last item from the `queue` is given to a `worker`. If the callback
+     * is omitted, `q.empty()` returns a promise for the next occurrence.
+     * @property {Function} drain - a function that sets a callback that is called
+     * when the last item from the `queue` has returned from the `worker`. If the
+     * callback is omitted, `q.drain()` returns a promise for the next occurrence.
+     * @property {Function} error - a function that sets a callback that is called
+     * when a task errors. Has the signature `function(error, task)`. If the
+     * callback is omitted, `error()` returns a promise that rejects on the next
+     * error.
+     * @property {boolean} paused - a boolean for determining whether the queue is
+     * in a paused state.
+     * @property {Function} pause - a function that pauses the processing of tasks
+     * until `resume()` is called. Invoke with `queue.pause()`.
+     * @property {Function} resume - a function that resumes the processing of
+     * queued tasks when the queue is paused. Invoke with `queue.resume()`.
+     * @property {Function} kill - a function that removes the `drain` callback and
+     * empties remaining tasks from the queue forcing it to go idle. No more tasks
+     * should be pushed to the queue after calling this function. Invoke with `queue.kill()`.
+     *
+     * @example
+     * const q = async.queue(worker, 2)
+     * q.push(item1)
+     * q.push(item2)
+     * q.push(item3)
+     * // queues are iterable, spread into an array to inspect
+     * const items = [...q] // [item1, item2, item3]
+     * // or use for of
+     * for (let item of q) {
+     *     console.log(item)
+     * }
+     *
+     * q.drain(() => {
+     *     console.log('all done')
+     * })
+     * // or
+     * await q.drain()
+     */
+
+    /**
+     * Creates a `queue` object with the specified `concurrency`. Tasks added to the
+     * `queue` are processed in parallel (up to the `concurrency` limit). If all
+     * `worker`s are in progress, the task is queued until one becomes available.
+     * Once a `worker` completes a `task`, that `task`'s callback is called.
+     *
+     * @name queue
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {AsyncFunction} worker - An async function for processing a queued task.
+     * If you want to handle errors from an individual task, pass a callback to
+     * `q.push()`. Invoked with (task, callback).
+     * @param {number} [concurrency=1] - An `integer` for determining how many
+     * `worker` functions should be run in parallel.  If omitted, the concurrency
+     * defaults to `1`.  If the concurrency is `0`, an error is thrown.
+     * @returns {module:ControlFlow.QueueObject} A queue object to manage the tasks. Callbacks can be
+     * attached as certain properties to listen for specific events during the
+     * lifecycle of the queue.
+     * @example
+     *
+     * // create a queue object with concurrency 2
+     * var q = async.queue(function(task, callback) {
+     *     console.log('hello ' + task.name);
+     *     callback();
+     * }, 2);
+     *
+     * // assign a callback
+     * q.drain(function() {
+     *     console.log('all items have been processed');
+     * });
+     * // or await the end
+     * await q.drain()
+     *
+     * // assign an error callback
+     * q.error(function(err, task) {
+     *     console.error('task experienced an error');
+     * });
+     *
+     * // add some items to the queue
+     * q.push({name: 'foo'}, function(err) {
+     *     console.log('finished processing foo');
+     * });
+     * // callback is optional
+     * q.push({name: 'bar'});
+     *
+     * // add some items to the queue (batch-wise)
+     * q.push([{name: 'baz'},{name: 'bay'},{name: 'bax'}], function(err) {
+     *     console.log('finished processing item');
+     * });
+     *
+     * // add some items to the front of the queue
+     * q.unshift({name: 'bar'}, function (err) {
+     *     console.log('finished processing bar');
+     * });
+     */
+    function queue$1 (worker, concurrency) {
+        var _worker = wrapAsync(worker);
+        return queue((items, cb) => {
+            _worker(items[0], cb);
+        }, concurrency, 1);
+    }
+
+    // Binary min-heap implementation used for priority queue.
+    // Implementation is stable, i.e. push time is considered for equal priorities
+    class Heap {
+        constructor() {
+            this.heap = [];
+            this.pushCount = Number.MIN_SAFE_INTEGER;
+        }
+
+        get length() {
+            return this.heap.length;
+        }
+
+        empty () {
+            this.heap = [];
+            return this;
+        }
+
+        percUp(index) {
+            let p;
+
+            while (index > 0 && smaller(this.heap[index], this.heap[p=parent(index)])) {
+                let t = this.heap[index];
+                this.heap[index] = this.heap[p];
+                this.heap[p] = t;
+
+                index = p;
+            }
+        }
+
+        percDown(index) {
+            let l;
+
+            while ((l=leftChi(index)) < this.heap.length) {
+                if (l+1 < this.heap.length && smaller(this.heap[l+1], this.heap[l])) {
+                    l = l+1;
+                }
+
+                if (smaller(this.heap[index], this.heap[l])) {
+                    break;
+                }
+
+                let t = this.heap[index];
+                this.heap[index] = this.heap[l];
+                this.heap[l] = t;
+
+                index = l;
+            }
+        }
+
+        push(node) {
+            node.pushCount = ++this.pushCount;
+            this.heap.push(node);
+            this.percUp(this.heap.length-1);
+        }
+
+        unshift(node) {
+            return this.heap.push(node);
+        }
+
+        shift() {
+            let [top] = this.heap;
+
+            this.heap[0] = this.heap[this.heap.length-1];
+            this.heap.pop();
+            this.percDown(0);
+
+            return top;
+        }
+
+        toArray() {
+            return [...this];
+        }
+
+        *[Symbol.iterator] () {
+            for (let i = 0; i < this.heap.length; i++) {
+                yield this.heap[i].data;
+            }
+        }
+
+        remove (testFn) {
+            let j = 0;
+            for (let i = 0; i < this.heap.length; i++) {
+                if (!testFn(this.heap[i])) {
+                    this.heap[j] = this.heap[i];
+                    j++;
+                }
+            }
+
+            this.heap.splice(j);
+
+            for (let i = parent(this.heap.length-1); i >= 0; i--) {
+                this.percDown(i);
+            }
+
+            return this;
+        }
+    }
+
+    function leftChi(i) {
+        return (i<<1)+1;
+    }
+
+    function parent(i) {
+        return ((i+1)>>1)-1;
+    }
+
+    function smaller(x, y) {
+        if (x.priority !== y.priority) {
+            return x.priority < y.priority;
+        }
+        else {
+            return x.pushCount < y.pushCount;
+        }
+    }
+
+    /**
+     * The same as [async.queue]{@link module:ControlFlow.queue} only tasks are assigned a priority and
+     * completed in ascending priority order.
+     *
+     * @name priorityQueue
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.queue]{@link module:ControlFlow.queue}
+     * @category Control Flow
+     * @param {AsyncFunction} worker - An async function for processing a queued task.
+     * If you want to handle errors from an individual task, pass a callback to
+     * `q.push()`.
+     * Invoked with (task, callback).
+     * @param {number} concurrency - An `integer` for determining how many `worker`
+     * functions should be run in parallel.  If omitted, the concurrency defaults to
+     * `1`.  If the concurrency is `0`, an error is thrown.
+     * @returns {module:ControlFlow.QueueObject} A priorityQueue object to manage the tasks. There are three
+     * differences between `queue` and `priorityQueue` objects:
+     * * `push(task, priority, [callback])` - `priority` should be a number. If an
+     *   array of `tasks` is given, all tasks will be assigned the same priority.
+     * * `pushAsync(task, priority, [callback])` - the same as `priorityQueue.push`,
+     *   except this returns a promise that rejects if an error occurs.
+     * * The `unshift` and `unshiftAsync` methods were removed.
+     */
+    function priorityQueue(worker, concurrency) {
+        // Start with a normal queue
+        var q = queue$1(worker, concurrency);
+
+        var {
+            push,
+            pushAsync
+        } = q;
+
+        q._tasks = new Heap();
+        q._createTaskItem = ({data, priority}, callback) => {
+            return {
+                data,
+                priority,
+                callback
+            };
+        };
+
+        function createDataItems(tasks, priority) {
+            if (!Array.isArray(tasks)) {
+                return {data: tasks, priority};
+            }
+            return tasks.map(data => { return {data, priority}; });
+        }
+
+        // Override push to accept second parameter representing priority
+        q.push = function(data, priority = 0, callback) {
+            return push(createDataItems(data, priority), callback);
+        };
+
+        q.pushAsync = function(data, priority = 0, callback) {
+            return pushAsync(createDataItems(data, priority), callback);
+        };
+
+        // Remove unshift functions
+        delete q.unshift;
+        delete q.unshiftAsync;
+
+        return q;
+    }
+
+    /**
+     * Runs the `tasks` array of functions in parallel, without waiting until the
+     * previous function has completed. Once any of the `tasks` complete or pass an
+     * error to its callback, the main `callback` is immediately called. It's
+     * equivalent to `Promise.race()`.
+     *
+     * @name race
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Array} tasks - An array containing [async functions]{@link AsyncFunction}
+     * to run. Each function can complete with an optional `result` value.
+     * @param {Function} callback - A callback to run once any of the functions have
+     * completed. This function gets an error or result from the first function that
+     * completed. Invoked with (err, result).
+     * @returns {Promise} a promise, if a callback is omitted
+     * @example
+     *
+     * async.race([
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'two');
+     *         }, 100);
+     *     }
+     * ],
+     * // main callback
+     * function(err, result) {
+     *     // the result will be equal to 'two' as it finishes earlier
+     * });
+     */
+    function race(tasks, callback) {
+        callback = once(callback);
+        if (!Array.isArray(tasks)) return callback(new TypeError('First argument to race must be an array of functions'));
+        if (!tasks.length) return callback();
+        for (var i = 0, l = tasks.length; i < l; i++) {
+            wrapAsync(tasks[i])(callback);
+        }
+    }
+
+    var race$1 = awaitify(race, 2);
+
+    /**
+     * Same as [`reduce`]{@link module:Collections.reduce}, only operates on `array` in reverse order.
+     *
+     * @name reduceRight
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.reduce]{@link module:Collections.reduce}
+     * @alias foldr
+     * @category Collection
+     * @param {Array} array - A collection to iterate over.
+     * @param {*} memo - The initial state of the reduction.
+     * @param {AsyncFunction} iteratee - A function applied to each item in the
+     * array to produce the next step in the reduction.
+     * The `iteratee` should complete with the next state of the reduction.
+     * If the iteratee completes with an error, the reduction is stopped and the
+     * main `callback` is immediately called with the error.
+     * Invoked with (memo, item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Result is the reduced value. Invoked with
+     * (err, result).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function reduceRight (array, memo, iteratee, callback) {
+        var reversed = [...array].reverse();
+        return reduce$1(reversed, memo, iteratee, callback);
+    }
+
+    /**
+     * Wraps the async function in another function that always completes with a
+     * result object, even when it errors.
+     *
+     * The result object has either the property `error` or `value`.
+     *
+     * @name reflect
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {AsyncFunction} fn - The async function you want to wrap
+     * @returns {Function} - A function that always passes null to it's callback as
+     * the error. The second argument to the callback will be an `object` with
+     * either an `error` or a `value` property.
+     * @example
+     *
+     * async.parallel([
+     *     async.reflect(function(callback) {
+     *         // do some stuff ...
+     *         callback(null, 'one');
+     *     }),
+     *     async.reflect(function(callback) {
+     *         // do some more stuff but error ...
+     *         callback('bad stuff happened');
+     *     }),
+     *     async.reflect(function(callback) {
+     *         // do some more stuff ...
+     *         callback(null, 'two');
+     *     })
+     * ],
+     * // optional callback
+     * function(err, results) {
+     *     // values
+     *     // results[0].value = 'one'
+     *     // results[1].error = 'bad stuff happened'
+     *     // results[2].value = 'two'
+     * });
+     */
+    function reflect(fn) {
+        var _fn = wrapAsync(fn);
+        return initialParams(function reflectOn(args, reflectCallback) {
+            args.push((error, ...cbArgs) => {
+                let retVal = {};
+                if (error) {
+                    retVal.error = error;
+                }
+                if (cbArgs.length > 0){
+                    var value = cbArgs;
+                    if (cbArgs.length <= 1) {
+                        [value] = cbArgs;
+                    }
+                    retVal.value = value;
+                }
+                reflectCallback(null, retVal);
+            });
+
+            return _fn.apply(this, args);
+        });
+    }
+
+    /**
+     * A helper function that wraps an array or an object of functions with `reflect`.
+     *
+     * @name reflectAll
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @see [async.reflect]{@link module:Utils.reflect}
+     * @category Util
+     * @param {Array|Object|Iterable} tasks - The collection of
+     * [async functions]{@link AsyncFunction} to wrap in `async.reflect`.
+     * @returns {Array} Returns an array of async functions, each wrapped in
+     * `async.reflect`
+     * @example
+     *
+     * let tasks = [
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     function(callback) {
+     *         // do some more stuff but error ...
+     *         callback(new Error('bad stuff happened'));
+     *     },
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'two');
+     *         }, 100);
+     *     }
+     * ];
+     *
+     * async.parallel(async.reflectAll(tasks),
+     * // optional callback
+     * function(err, results) {
+     *     // values
+     *     // results[0].value = 'one'
+     *     // results[1].error = Error('bad stuff happened')
+     *     // results[2].value = 'two'
+     * });
+     *
+     * // an example using an object instead of an array
+     * let tasks = {
+     *     one: function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     two: function(callback) {
+     *         callback('two');
+     *     },
+     *     three: function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'three');
+     *         }, 100);
+     *     }
+     * };
+     *
+     * async.parallel(async.reflectAll(tasks),
+     * // optional callback
+     * function(err, results) {
+     *     // values
+     *     // results.one.value = 'one'
+     *     // results.two.error = 'two'
+     *     // results.three.value = 'three'
+     * });
+     */
+    function reflectAll(tasks) {
+        var results;
+        if (Array.isArray(tasks)) {
+            results = tasks.map(reflect);
+        } else {
+            results = {};
+            Object.keys(tasks).forEach(key => {
+                results[key] = reflect.call(this, tasks[key]);
+            });
+        }
+        return results;
+    }
+
+    function reject(eachfn, arr, _iteratee, callback) {
+        const iteratee = wrapAsync(_iteratee);
+        return _filter(eachfn, arr, (value, cb) => {
+            iteratee(value, (err, v) => {
+                cb(err, !v);
+            });
+        }, callback);
+    }
+
+    /**
+     * The opposite of [`filter`]{@link module:Collections.filter}. Removes values that pass an `async` truth test.
+     *
+     * @name reject
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.filter]{@link module:Collections.filter}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {Function} iteratee - An async truth test to apply to each item in
+     * `coll`.
+     * The should complete with a boolean value as its `result`.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     *
+     * const fileList = ['dir1/file1.txt','dir2/file3.txt','dir3/file6.txt'];
+     *
+     * // asynchronous function that checks if a file exists
+     * function fileExists(file, callback) {
+     *    fs.access(file, fs.constants.F_OK, (err) => {
+     *        callback(null, !err);
+     *    });
+     * }
+     *
+     * // Using callbacks
+     * async.reject(fileList, fileExists, function(err, results) {
+     *    // [ 'dir3/file6.txt' ]
+     *    // results now equals an array of the non-existing files
+     * });
+     *
+     * // Using Promises
+     * async.reject(fileList, fileExists)
+     * .then( results => {
+     *     console.log(results);
+     *     // [ 'dir3/file6.txt' ]
+     *     // results now equals an array of the non-existing files
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.reject(fileList, fileExists);
+     *         console.log(results);
+     *         // [ 'dir3/file6.txt' ]
+     *         // results now equals an array of the non-existing files
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function reject$1 (coll, iteratee, callback) {
+        return reject(eachOf$1, coll, iteratee, callback)
+    }
+    var reject$2 = awaitify(reject$1, 3);
+
+    /**
+     * The same as [`reject`]{@link module:Collections.reject} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name rejectLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.reject]{@link module:Collections.reject}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {Function} iteratee - An async truth test to apply to each item in
+     * `coll`.
+     * The should complete with a boolean value as its `result`.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function rejectLimit (coll, limit, iteratee, callback) {
+        return reject(eachOfLimit(limit), coll, iteratee, callback)
+    }
+    var rejectLimit$1 = awaitify(rejectLimit, 4);
+
+    /**
+     * The same as [`reject`]{@link module:Collections.reject} but runs only a single async operation at a time.
+     *
+     * @name rejectSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.reject]{@link module:Collections.reject}
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {Function} iteratee - An async truth test to apply to each item in
+     * `coll`.
+     * The should complete with a boolean value as its `result`.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     */
+    function rejectSeries (coll, iteratee, callback) {
+        return reject(eachOfSeries$1, coll, iteratee, callback)
+    }
+    var rejectSeries$1 = awaitify(rejectSeries, 3);
+
+    function constant$1(value) {
+        return function () {
+            return value;
+        }
+    }
+
+    /**
+     * Attempts to get a successful response from `task` no more than `times` times
+     * before returning an error. If the task is successful, the `callback` will be
+     * passed the result of the successful task. If all attempts fail, the callback
+     * will be passed the error and result (if any) of the final attempt.
+     *
+     * @name retry
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @see [async.retryable]{@link module:ControlFlow.retryable}
+     * @param {Object|number} [opts = {times: 5, interval: 0}| 5] - Can be either an
+     * object with `times` and `interval` or a number.
+     * * `times` - The number of attempts to make before giving up.  The default
+     *   is `5`.
+     * * `interval` - The time to wait between retries, in milliseconds.  The
+     *   default is `0`. The interval may also be specified as a function of the
+     *   retry count (see example).
+     * * `errorFilter` - An optional synchronous function that is invoked on
+     *   erroneous result. If it returns `true` the retry attempts will continue;
+     *   if the function returns `false` the retry flow is aborted with the current
+     *   attempt's error and result being returned to the final callback.
+     *   Invoked with (err).
+     * * If `opts` is a number, the number specifies the number of times to retry,
+     *   with the default interval of `0`.
+     * @param {AsyncFunction} task - An async function to retry.
+     * Invoked with (callback).
+     * @param {Function} [callback] - An optional callback which is called when the
+     * task has succeeded, or after the final failed attempt. It receives the `err`
+     * and `result` arguments of the last attempt at completing the `task`. Invoked
+     * with (err, results).
+     * @returns {Promise} a promise if no callback provided
+     *
+     * @example
+     *
+     * // The `retry` function can be used as a stand-alone control flow by passing
+     * // a callback, as shown below:
+     *
+     * // try calling apiMethod 3 times
+     * async.retry(3, apiMethod, function(err, result) {
+     *     // do something with the result
+     * });
+     *
+     * // try calling apiMethod 3 times, waiting 200 ms between each retry
+     * async.retry({times: 3, interval: 200}, apiMethod, function(err, result) {
+     *     // do something with the result
+     * });
+     *
+     * // try calling apiMethod 10 times with exponential backoff
+     * // (i.e. intervals of 100, 200, 400, 800, 1600, ... milliseconds)
+     * async.retry({
+     *   times: 10,
+     *   interval: function(retryCount) {
+     *     return 50 * Math.pow(2, retryCount);
+     *   }
+     * }, apiMethod, function(err, result) {
+     *     // do something with the result
+     * });
+     *
+     * // try calling apiMethod the default 5 times no delay between each retry
+     * async.retry(apiMethod, function(err, result) {
+     *     // do something with the result
+     * });
+     *
+     * // try calling apiMethod only when error condition satisfies, all other
+     * // errors will abort the retry control flow and return to final callback
+     * async.retry({
+     *   errorFilter: function(err) {
+     *     return err.message === 'Temporary error'; // only retry on a specific error
+     *   }
+     * }, apiMethod, function(err, result) {
+     *     // do something with the result
+     * });
+     *
+     * // to retry individual methods that are not as reliable within other
+     * // control flow functions, use the `retryable` wrapper:
+     * async.auto({
+     *     users: api.getUsers.bind(api),
+     *     payments: async.retryable(3, api.getPayments.bind(api))
+     * }, function(err, results) {
+     *     // do something with the results
+     * });
+     *
+     */
+    const DEFAULT_TIMES = 5;
+    const DEFAULT_INTERVAL = 0;
+
+    function retry(opts, task, callback) {
+        var options = {
+            times: DEFAULT_TIMES,
+            intervalFunc: constant$1(DEFAULT_INTERVAL)
+        };
+
+        if (arguments.length < 3 && typeof opts === 'function') {
+            callback = task || promiseCallback();
+            task = opts;
+        } else {
+            parseTimes(options, opts);
+            callback = callback || promiseCallback();
+        }
+
+        if (typeof task !== 'function') {
+            throw new Error("Invalid arguments for async.retry");
+        }
+
+        var _task = wrapAsync(task);
+
+        var attempt = 1;
+        function retryAttempt() {
+            _task((err, ...args) => {
+                if (err === false) return
+                if (err && attempt++ < options.times &&
+                    (typeof options.errorFilter != 'function' ||
+                        options.errorFilter(err))) {
+                    setTimeout(retryAttempt, options.intervalFunc(attempt - 1));
+                } else {
+                    callback(err, ...args);
+                }
+            });
+        }
+
+        retryAttempt();
+        return callback[PROMISE_SYMBOL]
+    }
+
+    function parseTimes(acc, t) {
+        if (typeof t === 'object') {
+            acc.times = +t.times || DEFAULT_TIMES;
+
+            acc.intervalFunc = typeof t.interval === 'function' ?
+                t.interval :
+                constant$1(+t.interval || DEFAULT_INTERVAL);
+
+            acc.errorFilter = t.errorFilter;
+        } else if (typeof t === 'number' || typeof t === 'string') {
+            acc.times = +t || DEFAULT_TIMES;
+        } else {
+            throw new Error("Invalid arguments for async.retry");
+        }
+    }
+
+    /**
+     * A close relative of [`retry`]{@link module:ControlFlow.retry}.  This method
+     * wraps a task and makes it retryable, rather than immediately calling it
+     * with retries.
+     *
+     * @name retryable
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.retry]{@link module:ControlFlow.retry}
+     * @category Control Flow
+     * @param {Object|number} [opts = {times: 5, interval: 0}| 5] - optional
+     * options, exactly the same as from `retry`, except for a `opts.arity` that
+     * is the arity of the `task` function, defaulting to `task.length`
+     * @param {AsyncFunction} task - the asynchronous function to wrap.
+     * This function will be passed any arguments passed to the returned wrapper.
+     * Invoked with (...args, callback).
+     * @returns {AsyncFunction} The wrapped function, which when invoked, will
+     * retry on an error, based on the parameters specified in `opts`.
+     * This function will accept the same parameters as `task`.
+     * @example
+     *
+     * async.auto({
+     *     dep1: async.retryable(3, getFromFlakyService),
+     *     process: ["dep1", async.retryable(3, function (results, cb) {
+     *         maybeProcessData(results.dep1, cb);
+     *     })]
+     * }, callback);
+     */
+    function retryable (opts, task) {
+        if (!task) {
+            task = opts;
+            opts = null;
+        }
+        let arity = (opts && opts.arity) || task.length;
+        if (isAsync(task)) {
+            arity += 1;
+        }
+        var _task = wrapAsync(task);
+        return initialParams((args, callback) => {
+            if (args.length < arity - 1 || callback == null) {
+                args.push(callback);
+                callback = promiseCallback();
+            }
+            function taskFn(cb) {
+                _task(...args, cb);
+            }
+
+            if (opts) retry(opts, taskFn, callback);
+            else retry(taskFn, callback);
+
+            return callback[PROMISE_SYMBOL]
+        });
+    }
+
+    /**
+     * Run the functions in the `tasks` collection in series, each one running once
+     * the previous function has completed. If any functions in the series pass an
+     * error to its callback, no more functions are run, and `callback` is
+     * immediately called with the value of the error. Otherwise, `callback`
+     * receives an array of results when `tasks` have completed.
+     *
+     * It is also possible to use an object instead of an array. Each property will
+     * be run as a function, and the results will be passed to the final `callback`
+     * as an object instead of an array. This can be a more readable way of handling
+     *  results from {@link async.series}.
+     *
+     * **Note** that while many implementations preserve the order of object
+     * properties, the [ECMAScript Language Specification](http://www.ecma-international.org/ecma-262/5.1/#sec-8.6)
+     * explicitly states that
+     *
+     * > The mechanics and order of enumerating the properties is not specified.
+     *
+     * So if you rely on the order in which your series of functions are executed,
+     * and want this to work on all platforms, consider using an array.
+     *
+     * @name series
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection containing
+     * [async functions]{@link AsyncFunction} to run in series.
+     * Each function can complete with any number of optional `result` values.
+     * @param {Function} [callback] - An optional callback to run once all the
+     * functions have completed. This function gets a results array (or object)
+     * containing all the result arguments passed to the `task` callbacks. Invoked
+     * with (err, result).
+     * @return {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * //Using Callbacks
+     * async.series([
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             // do some async task
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             // then do another async task
+     *             callback(null, 'two');
+     *         }, 100);
+     *     }
+     * ], function(err, results) {
+     *     console.log(results);
+     *     // results is equal to ['one','two']
+     * });
+     *
+     * // an example using objects instead of arrays
+     * async.series({
+     *     one: function(callback) {
+     *         setTimeout(function() {
+     *             // do some async task
+     *             callback(null, 1);
+     *         }, 200);
+     *     },
+     *     two: function(callback) {
+     *         setTimeout(function() {
+     *             // then do another async task
+     *             callback(null, 2);
+     *         }, 100);
+     *     }
+     * }, function(err, results) {
+     *     console.log(results);
+     *     // results is equal to: { one: 1, two: 2 }
+     * });
+     *
+     * //Using Promises
+     * async.series([
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'one');
+     *         }, 200);
+     *     },
+     *     function(callback) {
+     *         setTimeout(function() {
+     *             callback(null, 'two');
+     *         }, 100);
+     *     }
+     * ]).then(results => {
+     *     console.log(results);
+     *     // results is equal to ['one','two']
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * // an example using an object instead of an array
+     * async.series({
+     *     one: function(callback) {
+     *         setTimeout(function() {
+     *             // do some async task
+     *             callback(null, 1);
+     *         }, 200);
+     *     },
+     *     two: function(callback) {
+     *         setTimeout(function() {
+     *             // then do another async task
+     *             callback(null, 2);
+     *         }, 100);
+     *     }
+     * }).then(results => {
+     *     console.log(results);
+     *     // results is equal to: { one: 1, two: 2 }
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * //Using async/await
+     * async () => {
+     *     try {
+     *         let results = await async.series([
+     *             function(callback) {
+     *                 setTimeout(function() {
+     *                     // do some async task
+     *                     callback(null, 'one');
+     *                 }, 200);
+     *             },
+     *             function(callback) {
+     *                 setTimeout(function() {
+     *                     // then do another async task
+     *                     callback(null, 'two');
+     *                 }, 100);
+     *             }
+     *         ]);
+     *         console.log(results);
+     *         // results is equal to ['one','two']
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * // an example using an object instead of an array
+     * async () => {
+     *     try {
+     *         let results = await async.parallel({
+     *             one: function(callback) {
+     *                 setTimeout(function() {
+     *                     // do some async task
+     *                     callback(null, 1);
+     *                 }, 200);
+     *             },
+     *            two: function(callback) {
+     *                 setTimeout(function() {
+     *                     // then do another async task
+     *                     callback(null, 2);
+     *                 }, 100);
+     *            }
+     *         });
+     *         console.log(results);
+     *         // results is equal to: { one: 1, two: 2 }
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function series(tasks, callback) {
+        return parallel(eachOfSeries$1, tasks, callback);
+    }
+
+    /**
+     * Returns `true` if at least one element in the `coll` satisfies an async test.
+     * If any iteratee call returns `true`, the main `callback` is immediately
+     * called.
+     *
+     * @name some
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @alias any
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async truth test to apply to each item
+     * in the collections in parallel.
+     * The iteratee should complete with a boolean `result` value.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called as soon as any
+     * iteratee returns `true`, or after all the iteratee functions have finished.
+     * Result will be either `true` or `false` depending on the values of the async
+     * tests. Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     * @example
+     *
+     * // dir1 is a directory that contains file1.txt, file2.txt
+     * // dir2 is a directory that contains file3.txt, file4.txt
+     * // dir3 is a directory that contains file5.txt
+     * // dir4 does not exist
+     *
+     * // asynchronous function that checks if a file exists
+     * function fileExists(file, callback) {
+     *    fs.access(file, fs.constants.F_OK, (err) => {
+     *        callback(null, !err);
+     *    });
+     * }
+     *
+     * // Using callbacks
+     * async.some(['dir1/missing.txt','dir2/missing.txt','dir3/file5.txt'], fileExists,
+     *    function(err, result) {
+     *        console.log(result);
+     *        // true
+     *        // result is true since some file in the list exists
+     *    }
+     *);
+     *
+     * async.some(['dir1/missing.txt','dir2/missing.txt','dir4/missing.txt'], fileExists,
+     *    function(err, result) {
+     *        console.log(result);
+     *        // false
+     *        // result is false since none of the files exists
+     *    }
+     *);
+     *
+     * // Using Promises
+     * async.some(['dir1/missing.txt','dir2/missing.txt','dir3/file5.txt'], fileExists)
+     * .then( result => {
+     *     console.log(result);
+     *     // true
+     *     // result is true since some file in the list exists
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * async.some(['dir1/missing.txt','dir2/missing.txt','dir4/missing.txt'], fileExists)
+     * .then( result => {
+     *     console.log(result);
+     *     // false
+     *     // result is false since none of the files exists
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.some(['dir1/missing.txt','dir2/missing.txt','dir3/file5.txt'], fileExists);
+     *         console.log(result);
+     *         // true
+     *         // result is true since some file in the list exists
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     * async () => {
+     *     try {
+     *         let result = await async.some(['dir1/missing.txt','dir2/missing.txt','dir4/missing.txt'], fileExists);
+     *         console.log(result);
+     *         // false
+     *         // result is false since none of the files exists
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function some(coll, iteratee, callback) {
+        return _createTester(Boolean, res => res)(eachOf$1, coll, iteratee, callback)
+    }
+    var some$1 = awaitify(some, 3);
+
+    /**
+     * The same as [`some`]{@link module:Collections.some} but runs a maximum of `limit` async operations at a time.
+     *
+     * @name someLimit
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.some]{@link module:Collections.some}
+     * @alias anyLimit
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - An async truth test to apply to each item
+     * in the collections in parallel.
+     * The iteratee should complete with a boolean `result` value.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called as soon as any
+     * iteratee returns `true`, or after all the iteratee functions have finished.
+     * Result will be either `true` or `false` depending on the values of the async
+     * tests. Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     */
+    function someLimit(coll, limit, iteratee, callback) {
+        return _createTester(Boolean, res => res)(eachOfLimit(limit), coll, iteratee, callback)
+    }
+    var someLimit$1 = awaitify(someLimit, 4);
+
+    /**
+     * The same as [`some`]{@link module:Collections.some} but runs only a single async operation at a time.
+     *
+     * @name someSeries
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @see [async.some]{@link module:Collections.some}
+     * @alias anySeries
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async truth test to apply to each item
+     * in the collections in series.
+     * The iteratee should complete with a boolean `result` value.
+     * Invoked with (item, callback).
+     * @param {Function} [callback] - A callback which is called as soon as any
+     * iteratee returns `true`, or after all the iteratee functions have finished.
+     * Result will be either `true` or `false` depending on the values of the async
+     * tests. Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     */
+    function someSeries(coll, iteratee, callback) {
+        return _createTester(Boolean, res => res)(eachOfSeries$1, coll, iteratee, callback)
+    }
+    var someSeries$1 = awaitify(someSeries, 3);
+
+    /**
+     * Sorts a list by the results of running each `coll` value through an async
+     * `iteratee`.
+     *
+     * @name sortBy
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {AsyncFunction} iteratee - An async function to apply to each item in
+     * `coll`.
+     * The iteratee should complete with a value to use as the sort criteria as
+     * its `result`.
+     * Invoked with (item, callback).
+     * @param {Function} callback - A callback which is called after all the
+     * `iteratee` functions have finished, or an error occurs. Results is the items
+     * from the original `coll` sorted by the values returned by the `iteratee`
+     * calls. Invoked with (err, results).
+     * @returns {Promise} a promise, if no callback passed
+     * @example
+     *
+     * // bigfile.txt is a file that is 251100 bytes in size
+     * // mediumfile.txt is a file that is 11000 bytes in size
+     * // smallfile.txt is a file that is 121 bytes in size
+     *
+     * // asynchronous function that returns the file size in bytes
+     * function getFileSizeInBytes(file, callback) {
+     *     fs.stat(file, function(err, stat) {
+     *         if (err) {
+     *             return callback(err);
+     *         }
+     *         callback(null, stat.size);
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes,
+     *     function(err, results) {
+     *         if (err) {
+     *             console.log(err);
+     *         } else {
+     *             console.log(results);
+     *             // results is now the original array of files sorted by
+     *             // file size (ascending by default), e.g.
+     *             // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
+     *         }
+     *     }
+     * );
+     *
+     * // By modifying the callback parameter the
+     * // sorting order can be influenced:
+     *
+     * // ascending order
+     * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], function(file, callback) {
+     *     getFileSizeInBytes(file, function(getFileSizeErr, fileSize) {
+     *         if (getFileSizeErr) return callback(getFileSizeErr);
+     *         callback(null, fileSize);
+     *     });
+     * }, function(err, results) {
+     *         if (err) {
+     *             console.log(err);
+     *         } else {
+     *             console.log(results);
+     *             // results is now the original array of files sorted by
+     *             // file size (ascending by default), e.g.
+     *             // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
+     *         }
+     *     }
+     * );
+     *
+     * // descending order
+     * async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], function(file, callback) {
+     *     getFileSizeInBytes(file, function(getFileSizeErr, fileSize) {
+     *         if (getFileSizeErr) {
+     *             return callback(getFileSizeErr);
+     *         }
+     *         callback(null, fileSize * -1);
+     *     });
+     * }, function(err, results) {
+     *         if (err) {
+     *             console.log(err);
+     *         } else {
+     *             console.log(results);
+     *             // results is now the original array of files sorted by
+     *             // file size (ascending by default), e.g.
+     *             // [ 'bigfile.txt', 'mediumfile.txt', 'smallfile.txt']
+     *         }
+     *     }
+     * );
+     *
+     * // Error handling
+     * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes,
+     *     function(err, results) {
+     *         if (err) {
+     *             console.log(err);
+     *             // [ Error: ENOENT: no such file or directory ]
+     *         } else {
+     *             console.log(results);
+     *         }
+     *     }
+     * );
+     *
+     * // Using Promises
+     * async.sortBy(['mediumfile.txt','smallfile.txt','bigfile.txt'], getFileSizeInBytes)
+     * .then( results => {
+     *     console.log(results);
+     *     // results is now the original array of files sorted by
+     *     // file size (ascending by default), e.g.
+     *     // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
+     * }).catch( err => {
+     *     console.log(err);
+     * });
+     *
+     * // Error handling
+     * async.sortBy(['mediumfile.txt','smallfile.txt','missingfile.txt'], getFileSizeInBytes)
+     * .then( results => {
+     *     console.log(results);
+     * }).catch( err => {
+     *     console.log(err);
+     *     // [ Error: ENOENT: no such file or directory ]
+     * });
+     *
+     * // Using async/await
+     * (async () => {
+     *     try {
+     *         let results = await async.sortBy(['bigfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes);
+     *         console.log(results);
+     *         // results is now the original array of files sorted by
+     *         // file size (ascending by default), e.g.
+     *         // [ 'smallfile.txt', 'mediumfile.txt', 'bigfile.txt']
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * })();
+     *
+     * // Error handling
+     * async () => {
+     *     try {
+     *         let results = await async.sortBy(['missingfile.txt','mediumfile.txt','smallfile.txt'], getFileSizeInBytes);
+     *         console.log(results);
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *         // [ Error: ENOENT: no such file or directory ]
+     *     }
+     * }
+     *
+     */
+    function sortBy (coll, iteratee, callback) {
+        var _iteratee = wrapAsync(iteratee);
+        return map$1(coll, (x, iterCb) => {
+            _iteratee(x, (err, criteria) => {
+                if (err) return iterCb(err);
+                iterCb(err, {value: x, criteria});
+            });
+        }, (err, results) => {
+            if (err) return callback(err);
+            callback(null, results.sort(comparator).map(v => v.value));
+        });
+
+        function comparator(left, right) {
+            var a = left.criteria, b = right.criteria;
+            return a < b ? -1 : a > b ? 1 : 0;
+        }
+    }
+    var sortBy$1 = awaitify(sortBy, 3);
+
+    /**
+     * Sets a time limit on an asynchronous function. If the function does not call
+     * its callback within the specified milliseconds, it will be called with a
+     * timeout error. The code property for the error object will be `'ETIMEDOUT'`.
+     *
+     * @name timeout
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @category Util
+     * @param {AsyncFunction} asyncFn - The async function to limit in time.
+     * @param {number} milliseconds - The specified time limit.
+     * @param {*} [info] - Any variable you want attached (`string`, `object`, etc)
+     * to timeout Error for more information..
+     * @returns {AsyncFunction} Returns a wrapped function that can be used with any
+     * of the control flow functions.
+     * Invoke this function with the same parameters as you would `asyncFunc`.
+     * @example
+     *
+     * function myFunction(foo, callback) {
+     *     doAsyncTask(foo, function(err, data) {
+     *         // handle errors
+     *         if (err) return callback(err);
+     *
+     *         // do some stuff ...
+     *
+     *         // return processed data
+     *         return callback(null, data);
+     *     });
+     * }
+     *
+     * var wrapped = async.timeout(myFunction, 1000);
+     *
+     * // call `wrapped` as you would `myFunction`
+     * wrapped({ bar: 'bar' }, function(err, data) {
+     *     // if `myFunction` takes < 1000 ms to execute, `err`
+     *     // and `data` will have their expected values
+     *
+     *     // else `err` will be an Error with the code 'ETIMEDOUT'
+     * });
+     */
+    function timeout(asyncFn, milliseconds, info) {
+        var fn = wrapAsync(asyncFn);
+
+        return initialParams((args, callback) => {
+            var timedOut = false;
+            var timer;
+
+            function timeoutCallback() {
+                var name = asyncFn.name || 'anonymous';
+                var error  = new Error('Callback function "' + name + '" timed out.');
+                error.code = 'ETIMEDOUT';
+                if (info) {
+                    error.info = info;
+                }
+                timedOut = true;
+                callback(error);
+            }
+
+            args.push((...cbArgs) => {
+                if (!timedOut) {
+                    callback(...cbArgs);
+                    clearTimeout(timer);
+                }
+            });
+
+            // setup timer and call original function
+            timer = setTimeout(timeoutCallback, milliseconds);
+            fn(...args);
+        });
+    }
+
+    function range(size) {
+        var result = Array(size);
+        while (size--) {
+            result[size] = size;
+        }
+        return result;
+    }
+
+    /**
+     * The same as [times]{@link module:ControlFlow.times} but runs a maximum of `limit` async operations at a
+     * time.
+     *
+     * @name timesLimit
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.times]{@link module:ControlFlow.times}
+     * @category Control Flow
+     * @param {number} count - The number of times to run the function.
+     * @param {number} limit - The maximum number of async operations at a time.
+     * @param {AsyncFunction} iteratee - The async function to call `n` times.
+     * Invoked with the iteration index and a callback: (n, next).
+     * @param {Function} callback - see [async.map]{@link module:Collections.map}.
+     * @returns {Promise} a promise, if no callback is provided
+     */
+    function timesLimit(count, limit, iteratee, callback) {
+        var _iteratee = wrapAsync(iteratee);
+        return mapLimit$1(range(count), limit, _iteratee, callback);
+    }
+
+    /**
+     * Calls the `iteratee` function `n` times, and accumulates results in the same
+     * manner you would use with [map]{@link module:Collections.map}.
+     *
+     * @name times
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.map]{@link module:Collections.map}
+     * @category Control Flow
+     * @param {number} n - The number of times to run the function.
+     * @param {AsyncFunction} iteratee - The async function to call `n` times.
+     * Invoked with the iteration index and a callback: (n, next).
+     * @param {Function} callback - see {@link module:Collections.map}.
+     * @returns {Promise} a promise, if no callback is provided
+     * @example
+     *
+     * // Pretend this is some complicated async factory
+     * var createUser = function(id, callback) {
+     *     callback(null, {
+     *         id: 'user' + id
+     *     });
+     * };
+     *
+     * // generate 5 users
+     * async.times(5, function(n, next) {
+     *     createUser(n, function(err, user) {
+     *         next(err, user);
+     *     });
+     * }, function(err, users) {
+     *     // we should now have 5 users
+     * });
+     */
+    function times (n, iteratee, callback) {
+        return timesLimit(n, Infinity, iteratee, callback)
+    }
+
+    /**
+     * The same as [times]{@link module:ControlFlow.times} but runs only a single async operation at a time.
+     *
+     * @name timesSeries
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.times]{@link module:ControlFlow.times}
+     * @category Control Flow
+     * @param {number} n - The number of times to run the function.
+     * @param {AsyncFunction} iteratee - The async function to call `n` times.
+     * Invoked with the iteration index and a callback: (n, next).
+     * @param {Function} callback - see {@link module:Collections.map}.
+     * @returns {Promise} a promise, if no callback is provided
+     */
+    function timesSeries (n, iteratee, callback) {
+        return timesLimit(n, 1, iteratee, callback)
+    }
+
+    /**
+     * A relative of `reduce`.  Takes an Object or Array, and iterates over each
+     * element in parallel, each step potentially mutating an `accumulator` value.
+     * The type of the accumulator defaults to the type of collection passed in.
+     *
+     * @name transform
+     * @static
+     * @memberOf module:Collections
+     * @method
+     * @category Collection
+     * @param {Array|Iterable|AsyncIterable|Object} coll - A collection to iterate over.
+     * @param {*} [accumulator] - The initial state of the transform.  If omitted,
+     * it will default to an empty Object or Array, depending on the type of `coll`
+     * @param {AsyncFunction} iteratee - A function applied to each item in the
+     * collection that potentially modifies the accumulator.
+     * Invoked with (accumulator, item, key, callback).
+     * @param {Function} [callback] - A callback which is called after all the
+     * `iteratee` functions have finished. Result is the transformed accumulator.
+     * Invoked with (err, result).
+     * @returns {Promise} a promise, if no callback provided
+     * @example
+     *
+     * // file1.txt is a file that is 1000 bytes in size
+     * // file2.txt is a file that is 2000 bytes in size
+     * // file3.txt is a file that is 3000 bytes in size
+     *
+     * // helper function that returns human-readable size format from bytes
+     * function formatBytes(bytes, decimals = 2) {
+     *   // implementation not included for brevity
+     *   return humanReadbleFilesize;
+     * }
+     *
+     * const fileList = ['file1.txt','file2.txt','file3.txt'];
+     *
+     * // asynchronous function that returns the file size, transformed to human-readable format
+     * // e.g. 1024 bytes = 1KB, 1234 bytes = 1.21 KB, 1048576 bytes = 1MB, etc.
+     * function transformFileSize(acc, value, key, callback) {
+     *     fs.stat(value, function(err, stat) {
+     *         if (err) {
+     *             return callback(err);
+     *         }
+     *         acc[key] = formatBytes(stat.size);
+     *         callback(null);
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.transform(fileList, transformFileSize, function(err, result) {
+     *     if(err) {
+     *         console.log(err);
+     *     } else {
+     *         console.log(result);
+     *         // [ '1000 Bytes', '1.95 KB', '2.93 KB' ]
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.transform(fileList, transformFileSize)
+     * .then(result => {
+     *     console.log(result);
+     *     // [ '1000 Bytes', '1.95 KB', '2.93 KB' ]
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * (async () => {
+     *     try {
+     *         let result = await async.transform(fileList, transformFileSize);
+     *         console.log(result);
+     *         // [ '1000 Bytes', '1.95 KB', '2.93 KB' ]
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * })();
+     *
+     * @example
+     *
+     * // file1.txt is a file that is 1000 bytes in size
+     * // file2.txt is a file that is 2000 bytes in size
+     * // file3.txt is a file that is 3000 bytes in size
+     *
+     * // helper function that returns human-readable size format from bytes
+     * function formatBytes(bytes, decimals = 2) {
+     *   // implementation not included for brevity
+     *   return humanReadbleFilesize;
+     * }
+     *
+     * const fileMap = { f1: 'file1.txt', f2: 'file2.txt', f3: 'file3.txt' };
+     *
+     * // asynchronous function that returns the file size, transformed to human-readable format
+     * // e.g. 1024 bytes = 1KB, 1234 bytes = 1.21 KB, 1048576 bytes = 1MB, etc.
+     * function transformFileSize(acc, value, key, callback) {
+     *     fs.stat(value, function(err, stat) {
+     *         if (err) {
+     *             return callback(err);
+     *         }
+     *         acc[key] = formatBytes(stat.size);
+     *         callback(null);
+     *     });
+     * }
+     *
+     * // Using callbacks
+     * async.transform(fileMap, transformFileSize, function(err, result) {
+     *     if(err) {
+     *         console.log(err);
+     *     } else {
+     *         console.log(result);
+     *         // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' }
+     *     }
+     * });
+     *
+     * // Using Promises
+     * async.transform(fileMap, transformFileSize)
+     * .then(result => {
+     *     console.log(result);
+     *     // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' }
+     * }).catch(err => {
+     *     console.log(err);
+     * });
+     *
+     * // Using async/await
+     * async () => {
+     *     try {
+     *         let result = await async.transform(fileMap, transformFileSize);
+     *         console.log(result);
+     *         // { f1: '1000 Bytes', f2: '1.95 KB', f3: '2.93 KB' }
+     *     }
+     *     catch (err) {
+     *         console.log(err);
+     *     }
+     * }
+     *
+     */
+    function transform (coll, accumulator, iteratee, callback) {
+        if (arguments.length <= 3 && typeof accumulator === 'function') {
+            callback = iteratee;
+            iteratee = accumulator;
+            accumulator = Array.isArray(coll) ? [] : {};
+        }
+        callback = once(callback || promiseCallback());
+        var _iteratee = wrapAsync(iteratee);
+
+        eachOf$1(coll, (v, k, cb) => {
+            _iteratee(accumulator, v, k, cb);
+        }, err => callback(err, accumulator));
+        return callback[PROMISE_SYMBOL]
+    }
+
+    /**
+     * It runs each task in series but stops whenever any of the functions were
+     * successful. If one of the tasks were successful, the `callback` will be
+     * passed the result of the successful task. If all tasks fail, the callback
+     * will be passed the error and result (if any) of the final attempt.
+     *
+     * @name tryEach
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Array|Iterable|AsyncIterable|Object} tasks - A collection containing functions to
+     * run, each function is passed a `callback(err, result)` it must call on
+     * completion with an error `err` (which can be `null`) and an optional `result`
+     * value.
+     * @param {Function} [callback] - An optional callback which is called when one
+     * of the tasks has succeeded, or all have failed. It receives the `err` and
+     * `result` arguments of the last attempt at completing the `task`. Invoked with
+     * (err, results).
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     * async.tryEach([
+     *     function getDataFromFirstWebsite(callback) {
+     *         // Try getting the data from the first website
+     *         callback(err, data);
+     *     },
+     *     function getDataFromSecondWebsite(callback) {
+     *         // First website failed,
+     *         // Try getting the data from the backup website
+     *         callback(err, data);
+     *     }
+     * ],
+     * // optional callback
+     * function(err, results) {
+     *     Now do something with the data.
+     * });
+     *
+     */
+    function tryEach(tasks, callback) {
+        var error = null;
+        var result;
+        return eachSeries$1(tasks, (task, taskCb) => {
+            wrapAsync(task)((err, ...args) => {
+                if (err === false) return taskCb(err);
+
+                if (args.length < 2) {
+                    [result] = args;
+                } else {
+                    result = args;
+                }
+                error = err;
+                taskCb(err ? null : {});
+            });
+        }, () => callback(error, result));
+    }
+
+    var tryEach$1 = awaitify(tryEach);
+
+    /**
+     * Undoes a [memoize]{@link module:Utils.memoize}d function, reverting it to the original,
+     * unmemoized form. Handy for testing.
+     *
+     * @name unmemoize
+     * @static
+     * @memberOf module:Utils
+     * @method
+     * @see [async.memoize]{@link module:Utils.memoize}
+     * @category Util
+     * @param {AsyncFunction} fn - the memoized function
+     * @returns {AsyncFunction} a function that calls the original unmemoized function
+     */
+    function unmemoize(fn) {
+        return (...args) => {
+            return (fn.unmemoized || fn)(...args);
+        };
+    }
+
+    /**
+     * Repeatedly call `iteratee`, while `test` returns `true`. Calls `callback` when
+     * stopped, or an error occurs.
+     *
+     * @name whilst
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {AsyncFunction} test - asynchronous truth test to perform before each
+     * execution of `iteratee`. Invoked with ().
+     * @param {AsyncFunction} iteratee - An async function which is called each time
+     * `test` passes. Invoked with (callback).
+     * @param {Function} [callback] - A callback which is called after the test
+     * function has failed and repeated execution of `iteratee` has stopped. `callback`
+     * will be passed an error and any arguments passed to the final `iteratee`'s
+     * callback. Invoked with (err, [results]);
+     * @returns {Promise} a promise, if no callback is passed
+     * @example
+     *
+     * var count = 0;
+     * async.whilst(
+     *     function test(cb) { cb(null, count < 5); },
+     *     function iter(callback) {
+     *         count++;
+     *         setTimeout(function() {
+     *             callback(null, count);
+     *         }, 1000);
+     *     },
+     *     function (err, n) {
+     *         // 5 seconds have passed, n = 5
+     *     }
+     * );
+     */
+    function whilst(test, iteratee, callback) {
+        callback = onlyOnce(callback);
+        var _fn = wrapAsync(iteratee);
+        var _test = wrapAsync(test);
+        var results = [];
+
+        function next(err, ...rest) {
+            if (err) return callback(err);
+            results = rest;
+            if (err === false) return;
+            _test(check);
+        }
+
+        function check(err, truth) {
+            if (err) return callback(err);
+            if (err === false) return;
+            if (!truth) return callback(null, ...results);
+            _fn(next);
+        }
+
+        return _test(check);
+    }
+    var whilst$1 = awaitify(whilst, 3);
+
+    /**
+     * Repeatedly call `iteratee` until `test` returns `true`. Calls `callback` when
+     * stopped, or an error occurs. `callback` will be passed an error and any
+     * arguments passed to the final `iteratee`'s callback.
+     *
+     * The inverse of [whilst]{@link module:ControlFlow.whilst}.
+     *
+     * @name until
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @see [async.whilst]{@link module:ControlFlow.whilst}
+     * @category Control Flow
+     * @param {AsyncFunction} test - asynchronous truth test to perform before each
+     * execution of `iteratee`. Invoked with (callback).
+     * @param {AsyncFunction} iteratee - An async function which is called each time
+     * `test` fails. Invoked with (callback).
+     * @param {Function} [callback] - A callback which is called after the test
+     * function has passed and repeated execution of `iteratee` has stopped. `callback`
+     * will be passed an error and any arguments passed to the final `iteratee`'s
+     * callback. Invoked with (err, [results]);
+     * @returns {Promise} a promise, if a callback is not passed
+     *
+     * @example
+     * const results = []
+     * let finished = false
+     * async.until(function test(cb) {
+     *     cb(null, finished)
+     * }, function iter(next) {
+     *     fetchPage(url, (err, body) => {
+     *         if (err) return next(err)
+     *         results = results.concat(body.objects)
+     *         finished = !!body.next
+     *         next(err)
+     *     })
+     * }, function done (err) {
+     *     // all pages have been fetched
+     * })
+     */
+    function until(test, iteratee, callback) {
+        const _test = wrapAsync(test);
+        return whilst$1((cb) => _test((err, truth) => cb (err, !truth)), iteratee, callback);
+    }
+
+    /**
+     * Runs the `tasks` array of functions in series, each passing their results to
+     * the next in the array. However, if any of the `tasks` pass an error to their
+     * own callback, the next function is not executed, and the main `callback` is
+     * immediately called with the error.
+     *
+     * @name waterfall
+     * @static
+     * @memberOf module:ControlFlow
+     * @method
+     * @category Control Flow
+     * @param {Array} tasks - An array of [async functions]{@link AsyncFunction}
+     * to run.
+     * Each function should complete with any number of `result` values.
+     * The `result` values will be passed as arguments, in order, to the next task.
+     * @param {Function} [callback] - An optional callback to run once all the
+     * functions have completed. This will be passed the results of the last task's
+     * callback. Invoked with (err, [results]).
+     * @returns {Promise} a promise, if a callback is omitted
+     * @example
+     *
+     * async.waterfall([
+     *     function(callback) {
+     *         callback(null, 'one', 'two');
+     *     },
+     *     function(arg1, arg2, callback) {
+     *         // arg1 now equals 'one' and arg2 now equals 'two'
+     *         callback(null, 'three');
+     *     },
+     *     function(arg1, callback) {
+     *         // arg1 now equals 'three'
+     *         callback(null, 'done');
+     *     }
+     * ], function (err, result) {
+     *     // result now equals 'done'
+     * });
+     *
+     * // Or, with named functions:
+     * async.waterfall([
+     *     myFirstFunction,
+     *     mySecondFunction,
+     *     myLastFunction,
+     * ], function (err, result) {
+     *     // result now equals 'done'
+     * });
+     * function myFirstFunction(callback) {
+     *     callback(null, 'one', 'two');
+     * }
+     * function mySecondFunction(arg1, arg2, callback) {
+     *     // arg1 now equals 'one' and arg2 now equals 'two'
+     *     callback(null, 'three');
+     * }
+     * function myLastFunction(arg1, callback) {
+     *     // arg1 now equals 'three'
+     *     callback(null, 'done');
+     * }
+     */
+    function waterfall (tasks, callback) {
+        callback = once(callback);
+        if (!Array.isArray(tasks)) return callback(new Error('First argument to waterfall must be an array of functions'));
+        if (!tasks.length) return callback();
+        var taskIndex = 0;
+
+        function nextTask(args) {
+            var task = wrapAsync(tasks[taskIndex++]);
+            task(...args, onlyOnce(next));
+        }
+
+        function next(err, ...args) {
+            if (err === false) return
+            if (err || taskIndex === tasks.length) {
+                return callback(err, ...args);
+            }
+            nextTask(args);
+        }
+
+        nextTask([]);
+    }
+
+    var waterfall$1 = awaitify(waterfall);
+
+    /**
+     * An "async function" in the context of Async is an asynchronous function with
+     * a variable number of parameters, with the final parameter being a callback.
+     * (`function (arg1, arg2, ..., callback) {}`)
+     * The final callback is of the form `callback(err, results...)`, which must be
+     * called once the function is completed.  The callback should be called with a
+     * Error as its first argument to signal that an error occurred.
+     * Otherwise, if no error occurred, it should be called with `null` as the first
+     * argument, and any additional `result` arguments that may apply, to signal
+     * successful completion.
+     * The callback must be called exactly once, ideally on a later tick of the
+     * JavaScript event loop.
+     *
+     * This type of function is also referred to as a "Node-style async function",
+     * or a "continuation passing-style function" (CPS). Most of the methods of this
+     * library are themselves CPS/Node-style async functions, or functions that
+     * return CPS/Node-style async functions.
+     *
+     * Wherever we accept a Node-style async function, we also directly accept an
+     * [ES2017 `async` function]{@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function}.
+     * In this case, the `async` function will not be passed a final callback
+     * argument, and any thrown error will be used as the `err` argument of the
+     * implicit callback, and the return value will be used as the `result` value.
+     * (i.e. a `rejected` of the returned Promise becomes the `err` callback
+     * argument, and a `resolved` value becomes the `result`.)
+     *
+     * Note, due to JavaScript limitations, we can only detect native `async`
+     * functions and not transpilied implementations.
+     * Your environment must have `async`/`await` support for this to work.
+     * (e.g. Node > v7.6, or a recent version of a modern browser).
+     * If you are using `async` functions through a transpiler (e.g. Babel), you
+     * must still wrap the function with [asyncify]{@link module:Utils.asyncify},
+     * because the `async function` will be compiled to an ordinary function that
+     * returns a promise.
+     *
+     * @typedef {Function} AsyncFunction
+     * @static
+     */
+
+    var index = {
+        apply,
+        applyEach: applyEach$1,
+        applyEachSeries,
+        asyncify,
+        auto,
+        autoInject,
+        cargo,
+        cargoQueue: cargo$1,
+        compose,
+        concat: concat$1,
+        concatLimit: concatLimit$1,
+        concatSeries: concatSeries$1,
+        constant,
+        detect: detect$1,
+        detectLimit: detectLimit$1,
+        detectSeries: detectSeries$1,
+        dir,
+        doUntil,
+        doWhilst: doWhilst$1,
+        each,
+        eachLimit: eachLimit$2,
+        eachOf: eachOf$1,
+        eachOfLimit: eachOfLimit$2,
+        eachOfSeries: eachOfSeries$1,
+        eachSeries: eachSeries$1,
+        ensureAsync,
+        every: every$1,
+        everyLimit: everyLimit$1,
+        everySeries: everySeries$1,
+        filter: filter$1,
+        filterLimit: filterLimit$1,
+        filterSeries: filterSeries$1,
+        forever: forever$1,
+        groupBy,
+        groupByLimit: groupByLimit$1,
+        groupBySeries,
+        log,
+        map: map$1,
+        mapLimit: mapLimit$1,
+        mapSeries: mapSeries$1,
+        mapValues,
+        mapValuesLimit: mapValuesLimit$1,
+        mapValuesSeries,
+        memoize,
+        nextTick,
+        parallel: parallel$1,
+        parallelLimit,
+        priorityQueue,
+        queue: queue$1,
+        race: race$1,
+        reduce: reduce$1,
+        reduceRight,
+        reflect,
+        reflectAll,
+        reject: reject$2,
+        rejectLimit: rejectLimit$1,
+        rejectSeries: rejectSeries$1,
+        retry,
+        retryable,
+        seq,
+        series,
+        setImmediate: setImmediate$1,
+        some: some$1,
+        someLimit: someLimit$1,
+        someSeries: someSeries$1,
+        sortBy: sortBy$1,
+        timeout,
+        times,
+        timesLimit,
+        timesSeries,
+        transform,
+        tryEach: tryEach$1,
+        unmemoize,
+        until,
+        waterfall: waterfall$1,
+        whilst: whilst$1,
+
+        // aliases
+        all: every$1,
+        allLimit: everyLimit$1,
+        allSeries: everySeries$1,
+        any: some$1,
+        anyLimit: someLimit$1,
+        anySeries: someSeries$1,
+        find: detect$1,
+        findLimit: detectLimit$1,
+        findSeries: detectSeries$1,
+        flatMap: concat$1,
+        flatMapLimit: concatLimit$1,
+        flatMapSeries: concatSeries$1,
+        forEach: each,
+        forEachSeries: eachSeries$1,
+        forEachLimit: eachLimit$2,
+        forEachOf: eachOf$1,
+        forEachOfSeries: eachOfSeries$1,
+        forEachOfLimit: eachOfLimit$2,
+        inject: reduce$1,
+        foldl: reduce$1,
+        foldr: reduceRight,
+        select: filter$1,
+        selectLimit: filterLimit$1,
+        selectSeries: filterSeries$1,
+        wrapSync: asyncify,
+        during: whilst$1,
+        doDuring: doWhilst$1
+    };
+
+    exports.default = index;
+    exports.apply = apply;
+    exports.applyEach = applyEach$1;
+    exports.applyEachSeries = applyEachSeries;
+    exports.asyncify = asyncify;
+    exports.auto = auto;
+    exports.autoInject = autoInject;
+    exports.cargo = cargo;
+    exports.cargoQueue = cargo$1;
+    exports.compose = compose;
+    exports.concat = concat$1;
+    exports.concatLimit = concatLimit$1;
+    exports.concatSeries = concatSeries$1;
+    exports.constant = constant;
+    exports.detect = detect$1;
+    exports.detectLimit = detectLimit$1;
+    exports.detectSeries = detectSeries$1;
+    exports.dir = dir;
+    exports.doUntil = doUntil;
+    exports.doWhilst = doWhilst$1;
+    exports.each = each;
+    exports.eachLimit = eachLimit$2;
+    exports.eachOf = eachOf$1;
+    exports.eachOfLimit = eachOfLimit$2;
+    exports.eachOfSeries = eachOfSeries$1;
+    exports.eachSeries = eachSeries$1;
+    exports.ensureAsync = ensureAsync;
+    exports.every = every$1;
+    exports.everyLimit = everyLimit$1;
+    exports.everySeries = everySeries$1;
+    exports.filter = filter$1;
+    exports.filterLimit = filterLimit$1;
+    exports.filterSeries = filterSeries$1;
+    exports.forever = forever$1;
+    exports.groupBy = groupBy;
+    exports.groupByLimit = groupByLimit$1;
+    exports.groupBySeries = groupBySeries;
+    exports.log = log;
+    exports.map = map$1;
+    exports.mapLimit = mapLimit$1;
+    exports.mapSeries = mapSeries$1;
+    exports.mapValues = mapValues;
+    exports.mapValuesLimit = mapValuesLimit$1;
+    exports.mapValuesSeries = mapValuesSeries;
+    exports.memoize = memoize;
+    exports.nextTick = nextTick;
+    exports.parallel = parallel$1;
+    exports.parallelLimit = parallelLimit;
+    exports.priorityQueue = priorityQueue;
+    exports.queue = queue$1;
+    exports.race = race$1;
+    exports.reduce = reduce$1;
+    exports.reduceRight = reduceRight;
+    exports.reflect = reflect;
+    exports.reflectAll = reflectAll;
+    exports.reject = reject$2;
+    exports.rejectLimit = rejectLimit$1;
+    exports.rejectSeries = rejectSeries$1;
+    exports.retry = retry;
+    exports.retryable = retryable;
+    exports.seq = seq;
+    exports.series = series;
+    exports.setImmediate = setImmediate$1;
+    exports.some = some$1;
+    exports.someLimit = someLimit$1;
+    exports.someSeries = someSeries$1;
+    exports.sortBy = sortBy$1;
+    exports.timeout = timeout;
+    exports.times = times;
+    exports.timesLimit = timesLimit;
+    exports.timesSeries = timesSeries;
+    exports.transform = transform;
+    exports.tryEach = tryEach$1;
+    exports.unmemoize = unmemoize;
+    exports.until = until;
+    exports.waterfall = waterfall$1;
+    exports.whilst = whilst$1;
+    exports.all = every$1;
+    exports.allLimit = everyLimit$1;
+    exports.allSeries = everySeries$1;
+    exports.any = some$1;
+    exports.anyLimit = someLimit$1;
+    exports.anySeries = someSeries$1;
+    exports.find = detect$1;
+    exports.findLimit = detectLimit$1;
+    exports.findSeries = detectSeries$1;
+    exports.flatMap = concat$1;
+    exports.flatMapLimit = concatLimit$1;
+    exports.flatMapSeries = concatSeries$1;
+    exports.forEach = each;
+    exports.forEachSeries = eachSeries$1;
+    exports.forEachLimit = eachLimit$2;
+    exports.forEachOf = eachOf$1;
+    exports.forEachOfSeries = eachOfSeries$1;
+    exports.forEachOfLimit = eachOfLimit$2;
+    exports.inject = reduce$1;
+    exports.foldl = reduce$1;
+    exports.foldr = reduceRight;
+    exports.select = filter$1;
+    exports.selectLimit = filterLimit$1;
+    exports.selectSeries = filterSeries$1;
+    exports.wrapSync = asyncify;
+    exports.during = whilst$1;
+    exports.doDuring = doWhilst$1;
+
+    Object.defineProperty(exports, '__esModule', { value: true });
+
+})));