public function to_postdata() {/*{{{*/
    $total = array();
    foreach ($this->parameters as $k => $v) {
      if (is_array($v)) {
        foreach ($v as $va) {
          $total[] = OAuthUtil::urlencode_rfc3986($k) . "[]=" . OAuthUtil::urlencode_rfc3986($va);
        }
      } else {
        $total[] = OAuthUtil::urlencode_rfc3986($k) . "=" . OAuthUtil::urlencode_rfc3986($v);
      }
    }
    $out = implode("&", $total);
    return $out;
  }