public static function calculateId($widget)
 {
     $dc = kDataCenterMgr::getCurrentDc();
     for ($i = 0; $i < 10; ++$i) {
         $id = $dc["id"] . '_' . kString::generateStringId();
         $existing_widget = widgetPeer::retrieveByPk($id);
         if (!$existing_widget) {
             return $id;
         }
     }
     die;
 }