/**
  * Format and sign an WP_OAuth / API request
  */
 function oAuthRequest($url, $method, $parameters)
 {
     if (strrpos($url, 'https://') !== 0 && strrpos($url, 'http://') !== 0) {
         $url = "{$this->host}{$url}.{$this->format}";
     }
     $request = WP_OAuthRequest::from_consumer_and_token($this->consumer, $this->token, $method, $url, $parameters);
     $request->sign_request($this->sha1_method, $this->consumer, $this->token);
     switch ($method) {
         case 'GET':
             return $this->http($request->to_url(), 'GET');
         default:
             return $this->http($request->get_normalized_http_url(), $method, $request->to_postdata());
     }
 }