code: protected Content getNavSummaryLink(ClassDoc cd, boolean link) {
          if (link) {
              if (cd == null) {
                  return writer.getHyperLink(SectionName.ENUM_CONSTANT_SUMMARY,
                          writer.getResource("doclet.navEnum"));
              } else {
                  return writer.getHyperLink(
                          SectionName.ENUM_CONSTANTS_INHERITANCE,
                          configuration.getClassName(cd), writer.getResource("doclet.navEnum"));
              }
          } else {
              return writer.getResource("doclet.navEnum");
          }
      }
docs: {@inheritDoc}