code: public String encodedFragment() {
          if (fragment == null) return null;
          int fragmentStart = url.indexOf('#') + 1;
          return url.substring(fragmentStart);
      }
docs: Returns this URL's encoded fragment, like {@code "abc"} for {@code http://host/#abc}. This
  returns null if the URL has no fragment.
  
  <p><table summary="">
  <tr><th>URL</th><th>{@code encodedFragment()}</th></tr>
  <tr><td>{@code http://host/}</td><td>null</td></tr>
  <tr><td>{@code http://host/#}</td><td>{@code ""}</td></tr>
  <tr><td>{@code http://host/#abc}</td><td>{@code "abc"}</td></tr>
  <tr><td>{@code http://host/#abc|def}</td><td>{@code "abc|def"}</td></tr>
  </table>