code: @Override
      public void notifySubscribers(final List<? extends Subscriber> subscribers, final SyndFeed value, final SubscriptionSummaryCallback callback) {
  
          String mimeType = null;
  
          if (value.getFeedType().startsWith("rss")) {
              mimeType = "application/rss+xml";
          } else {
              mimeType = "application/atom+xml";
          }
  
          final SyndFeedOutput output = new SyndFeedOutput();
          final ByteArrayOutputStream baos = new ByteArrayOutputStream();
  
          try {
              output.output(value, new OutputStreamWriter(baos));
              baos.close();
          } catch (final IOException ex) {
              LOG.error("Unable to output the feed", ex);
              throw new RuntimeException("Unable to output the feed.", ex);
          } catch (final FeedException ex) {
              LOG.error("Unable to output the feed", ex);
              throw new RuntimeException("Unable to output the feed.", ex);
          }
  
          final byte[] payload = baos.toByteArray();
  
          for (final Subscriber s : subscribers) {
              final Notification not = new Notification();
              not.callback = callback;
              not.lastRun = 0;
              not.mimeType = mimeType;
              not.payload = payload;
              not.retryCount = 0;
              not.subscriber = s;
              enqueueNotification(not);
          }
      }
docs: This method will serialize the synd feed and build Notifications for the implementation class
  to handle.
  
  @see enqueueNotification
  
  @param subscribers List of subscribers to notify
  @param value The SyndFeed object to send
  @param callback A callback that will be invoked each time a subscriber is notified.