public function preload($beans, $types) {
		foreach($types as $key => $type) {
			$map = array();
			$field = (is_numeric($key)) ? $type : $key;
			$ids = array();
			foreach($beans as $bean) {
				if($id = $bean->{$field.'_id'}){
					$ids[$id] = $id;
					if (!isset($map[$id])) $map[$id] = array();
					$map[$id][] = $bean;
				}
			}
			$parents = $this->batch($type,$ids);
			foreach($parents as $parent) {
				foreach($map[$parent->id] as $childBean) {
					$childBean->setProperty($field,$parent);
				}
			}
		}
	}