public function getIds($where = null, $order = null, $limit = null, $start = null)
 {
     $syncDone = $this->_synchronize();
     $ret = parent::getIds($where, $order, $limit, $start);
     $this->_unlockSync();
     if ($syncDone) {
         $this->_afterSync();
     }
     return $ret;
 }