code: public Content getTargetModulePackageLink(PackageElement pkg, String target,
              Content label, ModuleElement mdle) {
          return getHyperLink(pathString(pkg, DocPaths.PACKAGE_SUMMARY),
                  label, "", target);
      }
docs: Get Module Package link, with target frame.
  
  @param pkg the PackageElement
  @param target name of the target frame
  @param label tag for the link
  @param mdle the module being documented
  @return a content for the target module packages link