code: public static DocPath forPackage(PackageElement pkgElement) {
          return pkgElement == null || pkgElement.isUnnamed()
                  ? empty
                  : DocPath.create(pkgElement.getQualifiedName().toString().replace('.', '/'));
      }
docs: Return the path for a package.
  For example, if the package is java.lang,
  the path is java/lang.