/**
  * returns an instance of the language repository as singleton.
  *
  * @param void
  * @return tx_languagevisibility_languagerepository
  */
 public static function makeInstance()
 {
     if (!self::$instance instanceof tx_languagevisibility_languagerepository) {
         self::$instance = t3lib_div::makeInstance('tx_languagevisibility_languagerepository');
     }
     return self::$instance;
 }