code: @Override
      protected final void performAction(HistoryReference historyReference) {
          final SiteNode siteNode = getSiteNode(historyReference);
          if (siteNode != null) {
              performAction(siteNode);
          }
      }
docs: Calls the method {@code performAction(SiteNode)} passing as parameter the {@code SiteNode} extracted from the given
  {@code historyReference}.
  
  @see #performAction(SiteNode)