code: public static String getRawFragment(final URI uri, final boolean strict) {
          return esc(strict).escapeFragment(Strings.emptyToNull(uri.getRawFragment()));
      }
docs: Returns the raw (and normalized) fragment of the given URI, or null if it is empty.
  
  @param uri the URI to extract fragment from
  @param strict whether or not to do strict escaping
  @return the fragment or null if it is undefined