code: public boolean fbml_refreshRefUrl(URL url)
      throws FacebookException, IOException {
      return extractBoolean(this.callMethod(FacebookMethod.FBML_REFRESH_REF_URL,
                                            new Pair<String, CharSequence>("url", url.toString())));
    }
docs: Recaches the referenced url.
  @param url the URL to refresh
  @return boolean indicating whether the refresh succeeded