protected function getAppropriateTransport($flags)
    {
        if ($flags & ApiRequestOption::NO_RESPONSE) {
            $transport = $this->getAsyncTransport();
            if (is_null($transport)) {
                $transport = $this->getTransport();
            } else {
                $fallback = $this->getTransport();
                if ($fallback) {
                    $this->setFallbackTransport($fallback);
                }
            }
        } else {
            $transport = $this->getTransport();
        }

        return $transport;
    }