code: protected void notifyError(String message, Throwable error)
     {
        synchronized (listeners)
        {
           Thread notifier =
              new ErrorNotifyThread(listeners.toArray(new BackupJobListener[listeners.size()]), this, message, error);
           notifier.start();
        }
     }
docs: Notify all listeners about an error
  
  @param error
  - Throwable instance