code: public Content getPackageHeader(String packageName) {
          Content heading = HtmlTree.HEADING(HtmlConstants.PACKAGE_HEADING, true,
                  packageLabel);
          heading.addContent(getSpace());
          heading.addContent(packageName);
          return heading;
      }
docs: Get the given package header.
  
  @param packageName the package header to write
  @return a content tree for the package header