private function matchValueArgument(PropertyValue $propertyValue, $propertystring, $valuestring)
 {
     if ($propertyValue->getPropertyTypeID() === '_wpg') {
         $matches = array();
         preg_match_all('/\\[\\[([^\\[\\]]*)\\]\\]/u', $valuestring, $matches);
         $objects = $matches[1];
         if (count($objects) == 0) {
             if (trim($valuestring) !== '') {
                 $this->addDataValue($propertystring, $valuestring);
             }
         } else {
             foreach ($objects as $object) {
                 $this->addDataValue($propertystring, $object);
             }
         }
     } elseif (trim($valuestring) !== '') {
         $this->addDataValue($propertystring, $valuestring);
     }
     // $value = \SMW\DataValueFactory::getInstance()->newDataValueByProperty( $property->getDataItem(), $valuestring );
     // if (!$value->isValid()) continue;
 }