public function delete(User $user)
 {
     $dn = 'uid=' . $user->getUsername() . ',ou=users,' . $this->baseDn;
     if ($this->client->isEntityExist($dn)) {
         $this->client->delete($dn);
     }
     foreach ($user->getServices() as $service) {
         $dn = 'uid=' . $user->getUsername() . ',ou=users,dc=' . $service->getName() . ',' . $this->baseDn;
         if ($this->client->isEntityExist($dn)) {
             $this->client->delete($dn);
         }
     }
 }