code: protected Content getNavLinkClass() {
          Content linkContent = getLink(new LinkInfoImpl(
                  configuration, LinkInfoImpl.Kind.CLASS_USE_HEADER, classdoc)
                  .label(configuration.getText("doclet.Class")));
          Content li = HtmlTree.LI(linkContent);
          return li;
      }
docs: Get class page link.
  
  @return a content tree for the class page link