/**
  *
  * change the language loader method
  *
  */
 public static function setLanguageLoader($loader)
 {
     //make sure the loader is ok
     if (!is_callable($loader)) {
         throw new Exception(SyC::t('sdk', "The language loader is not a valid callback"));
     }
     self::$loadLanguage = $loader;
     //reset the old messages, so that they are reloaded with the new loader
     self::$_messages = null;
 }