code: protected Content getPackageUseHeader() {
          String packageText = configuration.getText("doclet.Package");
          String name = pkgdoc.name();
          String title = configuration.getText("doclet.Window_ClassUse_Header",
                  packageText, name);
          Content bodyTree = getBody(true, getWindowTitle(title));
          addTop(bodyTree);
          addNavLinks(true, bodyTree);
          ContentBuilder headContent = new ContentBuilder();
          headContent.addContent(getResource("doclet.ClassUse_Title", packageText));
          headContent.addContent(new HtmlTree(HtmlTag.BR));
          headContent.addContent(name);
          Content heading = HtmlTree.HEADING(HtmlConstants.TITLE_HEADING, true,
                  HtmlStyle.title, headContent);
          Content div = HtmlTree.DIV(HtmlStyle.header, heading);
          bodyTree.addContent(div);
          return bodyTree;
      }
docs: Get the header for the package use listing.
  
  @return a content tree representing the package use header