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());
}
}
