code: protected Content getNavSummaryLink(ClassDoc cd, boolean link) {
          if (link) {
              if (cd == null) {
                  return writer.getHyperLink(
                          SectionName.NESTED_CLASS_SUMMARY,
                          writer.getResource("doclet.navNested"));
              } else {
                  return writer.getHyperLink(
                          SectionName.NESTED_CLASSES_INHERITANCE,
                          cd.qualifiedName(), writer.getResource("doclet.navNested"));
              }
          } else {
              return writer.getResource("doclet.navNested");
          }
      }
docs: {@inheritDoc}