/**
   * 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;
  }