code: protected void addNavSummaryLink(SortedSet<? extends Element> members,
              VisibleMemberMap visibleMemberMap, Content liNav) {
          if (!members.isEmpty()) {
              liNav.addContent(getNavSummaryLink(null, true));
              return;
          }
  
          TypeElement superClass = utils.getSuperClass(typeElement);
          while (superClass != null) {
              if (visibleMemberMap.hasMembers(superClass)) {
                  liNav.addContent(getNavSummaryLink(superClass, true));
                  return;
              }
              superClass = utils.getSuperClass(superClass);
          }
          liNav.addContent(getNavSummaryLink(null, false));
      }
docs: Add the navigation summary link.
  
  @param members members to be linked
  @param visibleMemberMap the visible inherited members map
  @param liNav the content tree to which the navigation summary link will be added