protected function request($url, $method, $data = null)
    {
        $this->testLogin();
        try {
            $response = $this->transport->send(
                $url, $method, $data, array(
                'Content-Type: ' . $this->mapper->getContentType(),
                )
            );
        } catch (HttpStatusException $e) {
            $message = $e->getMessage();
            if ($e->getCode() == 403 || $e->getCode() == 422) {
                $this->errors = $this->mapper->mapFromStorage($this->transport->getLastResponse());
                if ($this->errors instanceof ErrorArray && count($this->errors) > 0) {
                    $message .= PHP_EOL . 'Errors:' . PHP_EOL . $this->errors;
                }
            }

            if (self::$debug) {
                printf(
                    'Url: %s' . PHP_EOL . 'Method: %s' . PHP_EOL . 'Data: %s', $url, $method, $data
                );
            }

            switch ($e->getCode()) {
                case 401:
                    throw new NotLoggedInException($message, 0, $e);
                    break;
                case 403:
                    throw new ForbiddenException($message, 0, $e);
                    break;
                case 404:
                    throw new NotFoundException($message, 0, $e);
                    break;
                case 406:
                case 422:
                    throw new NotValidException($message, 0, $e);
                    break;
                default:
                    $message = 'Unknown error; check https://github.com/bluetools/moneybird_php_api/wiki/Common-errors';
                // no break
                case 500:
                case 501:
                    throw new ServerErrorException($message, 0, $e);
                    break;
            }
        }

        return $response;
    }