public function addSubunit(Subunit $parentSubunit, Subunit $subunit) { try { $subunit->setId(0); $subunit->getNode()->insertAsLastChildOf($parentSubunit); $parentSubunit->setRgt($parentSubunit->getRgt() + 2); $parentSubunit->save(); return true; } catch (Exception $e) { throw new DaoException($e->getMessage()); } }