docs: public static SyndFeed combineFeeds(final SyndFeed originalFeed, final SyndFeed newFeed) {
          try {
              final SyndFeed result = (SyndFeed) newFeed.clone();
              result.getEntries().addAll(result.getEntries().size(), originalFeed.getEntries());
              return result;
          } catch (final CloneNotSupportedException e) {
              final IllegalArgumentException iae = new IllegalArgumentException("Cannot clone feed");
              iae.initCause(e);
              throw iae;
          }
      }