public function deleteSubunit(Subunit $subunit)
{
try {
$q = Doctrine_Query::create()->delete('Subunit')->where('lft >= ?', $subunit->getLft())->andWhere('rgt <= ?', $subunit->getRgt());
$q->execute();
return true;
} catch (Exception $e) {
throw new DaoException($e->getMessage());
}
}
