function concatSeries(coll, iteratee, callback) {
        return concatLimit$1(coll, 1, iteratee, callback)
    }
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