private function getDeletionPreventingParents() {
        $parentEntities = array();
        foreach($this->getModelBuilder()->getRelationships() as $relationship) {
            if($relationship->isPlural() && !$relationship->isNullable() && $relationship->getAction() != 'ACTION_CASCADE') {
                $parentEntities[] = $relationship->getAlias();
            }
        }

        return $parentEntities;
    }