/** * returns a unique key for an element * * @param $element * @return string */ public static function getUniqueKey($element) { if ($element instanceof Object\AbstractObject) { return Object\Service::getUniqueKey($element); } elseif ($element instanceof Document) { return Document\Service::getUniqueKey($element); } elseif ($element instanceof Asset) { return Asset\Service::getUniqueKey($element); } }