text: import noop from 'lodash-es/noop';
  import mapLimit from './mapLimit';
  import wrapAsync from './internal/wrapAsync';
  /**
   * 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|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.
   */
  export default function(coll, limit, iteratee, callback) {
      callback = callback || noop;
      var _iteratee = wrapAsync(iteratee);
      mapLimit(coll, limit, function(val, callback) {
          _iteratee(val, function(err, key) {
              if (err) return callback(err);
              return callback(null, {key: key, val: val});
          });
      }, function(err, mapResults) {
          var result = {};
          // from MDN, handle object having an `hasOwnProperty` prop
          var hasOwnProperty = Object.prototype.hasOwnProperty;
  
          for (var i = 0; i < mapResults.length; i++) {
              if (mapResults[i]) {
                  var key = mapResults[i].key;
                  var val = mapResults[i].val;
  
                  if (hasOwnProperty.call(result, key)) {
                      result[key].push(val);
                  } else {
                      result[key] = [val];
                  }
              }
          }
  
          return callback(err, result);
      });
  };
  