code: protected void generateClassUseFile() throws DocFileIOException {
          HtmlTree body = getClassUseHeader();
          HtmlTree div = new HtmlTree(HtmlTag.DIV);
          div.addStyle(HtmlStyle.classUseContainer);
          if (pkgSet.size() > 0) {
              addClassUse(div);
          } else {
              div.addContent(contents.getContent("doclet.ClassUse_No.usage.of.0",
                      utils.getFullyQualifiedName(typeElement)));
          }
          if (configuration.allowTag(HtmlTag.MAIN)) {
              mainTree.addContent(div);
              body.addContent(mainTree);
          } else {
              body.addContent(div);
          }
          HtmlTree htmlTree = (configuration.allowTag(HtmlTag.FOOTER))
                  ? HtmlTree.FOOTER()
                  : body;
          addNavLinks(false, htmlTree);
          addBottom(htmlTree);
          if (configuration.allowTag(HtmlTag.FOOTER)) {
              body.addContent(htmlTree);
          }
          printHtmlDocument(null, true, body);
      }
docs: Generate the class use elements.
  
  @throws DocFileIOException if there is a problem while generating the documentation