code: protected void generateClassUseFile() throws IOException {
          Content body = getClassUseHeader();
          HtmlTree div = new HtmlTree(HtmlTag.DIV);
          div.addStyle(HtmlStyle.classUseContainer);
          if (pkgSet.size() > 0) {
              addClassUse(div);
          } else {
              div.addContent(getResource("doclet.ClassUse_No.usage.of.0",
                      classdoc.qualifiedName()));
          }
          body.addContent(div);
          addNavLinks(false, body);
          addBottom(body);
          printHtmlDocument(null, true, body);
      }
docs: Generate the class use list.