/**
   * Place to put some hacks if needed on incoming requests.
   *
   * @param event the incoming request event.
   * @return status <code>true</code> if we don't need to process this message, just discard it and
   *     <code>false</code> otherwise.
   */
  private boolean applyNonConformanceHacks(RequestEvent event) {
    Request request = event.getRequest();
    try {
      /*
       * Max-Forwards is required, yet there are UAs which do not
       * place it. SipProvider#getNewServerTransaction(Request)
       * will throw an exception in the case of a missing
       * Max-Forwards header and this method will eventually just
       * log it thus ignoring the whole event.
       */
      if (request.getHeader(MaxForwardsHeader.NAME) == null) {
        // it appears that some buggy providers do send requests
        // with no Max-Forwards headers, as we are at application level
        // and we know there will be no endless loops
        // there is no problem of adding headers and process normally
        // this messages
        MaxForwardsHeader maxForwards =
            SipFactory.getInstance().createHeaderFactory().createMaxForwardsHeader(70);
        request.setHeader(maxForwards);
      }
    } catch (Throwable ex) {
      logger.warn("Cannot apply incoming request modification!", ex);
    }

    try {
      // using asterisk voice mail initial notify for messages
      // is ok, but on the fly received messages their notify comes
      // without subscription-state, so we add it in order to be able to
      // process message.
      if (request.getMethod().equals(Request.NOTIFY)
          && request.getHeader(EventHeader.NAME) != null
          && ((EventHeader) request.getHeader(EventHeader.NAME))
              .getEventType()
              .equals(OperationSetMessageWaitingSipImpl.EVENT_PACKAGE)
          && request.getHeader(SubscriptionStateHeader.NAME) == null) {
        request.addHeader(
            new HeaderFactoryImpl().createSubscriptionStateHeader(SubscriptionStateHeader.ACTIVE));
      }
    } catch (Throwable ex) {
      logger.warn("Cannot apply incoming request modification!", ex);
    }

    try {
      // receiving notify message without subscription state
      // used for keep-alive pings, they have done their job
      // and are no more need. Skip processing them to avoid
      // filling logs with unneeded exceptions.
      if (request.getMethod().equals(Request.NOTIFY)
          && request.getHeader(SubscriptionStateHeader.NAME) == null) {
        return true;
      }
    } catch (Throwable ex) {
      logger.warn("Cannot apply incoming request modification!", ex);
    }

    return false;
  }
  /**
   * Dispatches the event received from a JAIN-SIP <tt>SipProvider</tt> to one of our "candidate
   * recipient" listeners.
   *
   * @param event the event received for a <tt>SipProvider</tt>.
   */
  public void processResponse(ResponseEvent event) {
    try {
      // we don't have to accept the transaction since we
      // created the request
      ClientTransaction transaction = event.getClientTransaction();
      if (logger.isTraceEnabled())
        logger.trace(
            "received response: "
                + event.getResponse().getStatusCode()
                + " "
                + event.getResponse().getReasonPhrase());

      if (transaction == null) {
        logger.warn("Transaction is null, probably already expired!");
        return;
      }

      ProtocolProviderServiceSipImpl service = getServiceData(transaction);
      if (service != null) {
        // Mark the dialog for the dispatching of later in-dialog
        // responses. If there is no dialog then the initial request
        // sure is marked otherwise we won't have found the service with
        // getServiceData(). The request has to be marked in case we
        // receive one more response in an out-of-dialog transaction.
        if (event.getDialog() != null) {
          SipApplicationData.setApplicationData(
              event.getDialog(), SipApplicationData.KEY_SERVICE, service);
        }
        service.processResponse(event);
      } else {
        logger.error(
            "We received a response which "
                + "wasn't marked, please report this to "
                + "*****@*****.**");
      }
    } catch (Throwable exc) {
      // any exception thrown within our code should be caught here
      // so that we could log it rather than interrupt stack activity with
      // it.
      this.logApplicationException(DialogTerminatedEvent.class, exc);
    }
  }