Izmjenjena struktura, dodan backand

web/node_modules/es5-ext/array/#/group.js

@@ -0,0 +1,28 @@
+// Inspired by Underscore's groupBy:
+// http://documentcloud.github.com/underscore/#groupBy
+
+"use strict";
+
+var callable = require("../../object/valid-callable")
+  , value    = require("../../object/valid-value")
+  , forEach  = Array.prototype.forEach
+  , apply    = Function.prototype.apply;
+
+module.exports = function (cb /*, thisArg*/) {
+	var result;
+
+	value(this);
+	callable(cb);
+
+	result = Object.create(null);
+	forEach.call(
+		this,
+		function (item) {
+			var key = apply.call(cb, this, arguments);
+			if (!result[key]) result[key] = [];
+			result[key].push(item);
+		},
+		arguments[1]
+	);
+	return result;
+};