public function doServiceRequest($service, $method, $format, $data)
    {

        $header = ToolConsumer::addSignature($service->endpoint, $this->getKey(), $this->secret, $data, $method, $format);

// Connect to tool consumer
        $http = new HTTPMessage($service->endpoint, $method, $data, $header);
// Parse JSON response
        if ($http->send() && !empty($http->response)) {
            $http->responseJson = json_decode($http->response);
            $http->ok = !is_null($http->responseJson);
        }

        return $http;

    }