code: public void processTimeout(TimeoutEvent arg0) {
      synchronized (listeners) {
        Iterator<SipListener> iter = listeners.iterator();
        while (iter.hasNext() == true) {
          SipListener listener = (SipListener) iter.next();
          listener.processTimeout(arg0);
        }
      }
    }
docs: FOR INTERNAL USE ONLY. Not to be used by a test program.