code: @Override
      public Document generate(final WireFeed feed) throws IllegalArgumentException, FeedException {
          final Document document = super.generate(feed);
          document.getRootElement().setAttribute("version", "2.0");
          return document;
      }
docs: Creates an XML document (JDOM) for the given feed bean.
  
  @param feed the feed bean to generate the XML document from.
  @return the generated XML document (JDOM).
  @throws IllegalArgumentException thrown if the type of the given feed bean does not match with the type of the
  WireFeedGenerator.
  @throws FeedException thrown if the XML Document could not be created.