mcaskill

<?php

if (!function_exists('array_group_by')) {
	/**
	 * Groups an array by a given key.
	 *
	 * Groups an array into arrays by a given key, or set of keys, shared between all array members.
	 *
	 * Based on {@author Jake Zatecky}'s {@link https://github.com/jakezatecky/array_group_by array_group_by()} function.
	 * This variant allows $key to be closures.