docs: public void sendUpdateNotification(final String topic, final SyndFeed feed) throws NotificationException {
          for (final SyndLink link : feed.getLinks()) {
              if ("hub".equals(link.getRel())) {
                  sendUpdateNotification(link.getRel(), topic);
  
                  return;
              }
          }
          throw new NotificationException("Hub link not found.");
      }