code: private static Opt<String> readFragment(final URI link) {
          final Opt<String> fragment;
          if (link.getRawFragment() == null) {
              fragment = new Opt.Empty<>();
          } else {
              fragment = new Opt.Single<>(link.getRawFragment());
          }
          return fragment;
      }
docs: Read fragment part from the given URI.
  @param link The link from which the fragment needs to be returned.
  @return Opt with fragment or empty if there is no fragment.