public static function doRequest($httpMethod, $url, $parameters, $authHandlers, $contentType = ContentType::FORM, $encodeJson = true)
 {
     HttpUtils::cleanParameters($parameters);
     if ($authHandlers == null) {
         $authHandlers = array();
     }
     self::validateRequest($httpMethod, $url, $parameters, $authHandlers, $contentType);
     $response = self::execRequest($httpMethod, $url, $parameters, $authHandlers, $contentType, $encodeJson);
     return $response;
 }