Collection::group_by().php

<?php

	public static function group_by(Array $objects, $group_by_property)
	{
		$grouped_objects = [];
		
		foreach($objects as $object)
		{
			$property_value = $object->{$group_by_property};
			
			$grouped_objects[$property_value][] = $object;	
		}

		return $grouped_objects;
	}