Bump to v4.1.0.

_createAggregator.js

@@ -0,0 +1,21 @@
+define(['./_arrayAggregator', './_baseAggregator', './_baseIteratee', './isArray'], function(arrayAggregator, baseAggregator, baseIteratee, isArray) {
+
+  /**
+   * Creates a function like `_.groupBy`.
+   *
+   * @private
+   * @param {Function} setter The function to set accumulator values.
+   * @param {Function} [initializer] The accumulator object initializer.
+   * @returns {Function} Returns the new aggregator function.
+   */
+  function createAggregator(setter, initializer) {
+    return function(collection, iteratee) {
+      var func = isArray(collection) ? arrayAggregator : baseAggregator,
+          accumulator = initializer ? initializer() : {};
+
+      return func(collection, setter, baseIteratee(iteratee), accumulator);
+    };
+  }
+
+  return createAggregator;
+});