protected function _toObjectId(Object $pObject, $pUseSerializationName, $pDateTimeZone, &$pMainForeignObjects = null)
 {
     $lId = parent::_toObjectId($pObject, $pUseSerializationName, $pMainForeignObjects);
     if (is_array($pMainForeignObjects) && !(array_key_exists($this->mModelName, $pMainForeignObjects) && array_key_exists($lId, $pMainForeignObjects[$this->mModelName]))) {
         $pMainForeignObjects[$this->mModelName][$lId] = $this->_toObject($pObject, $pUseSerializationName, $pDateTimeZone, $pMainForeignObjects);
     }
     return $lId;
 }