/**
  * Allow nonadmin requests to call lang functions.
  * normally, an error would be generated if calling core lang functions from an frontend action.
  * this method will disable or enable that check.
  *
  * @internal
  * @param boolean flag
  * @return void.
  */
 public static function allow_nonadmin_lang($flag = TRUE)
 {
     self::$_allow_nonadmin_lang = $flag;
 }