/**
  * Deletes the mapping for a username and a specific bakkend
  *
  * @return
  * @access private
  */
 private static function CommandUnmap()
 {
     if (ZPushAdmin::RemoveUsernameMapping(self::$user, self::$backend)) {
         printf("Successfully unmapped username.\n");
     } else {
         echo ZLog::GetLastMessage(LOGLEVEL_ERROR) . "\n";
     }
 }