Mdb\PayPal\Ipn\Service\GuzzleService::verifyIpnMessage PHP Метод

    public function verifyIpnMessage(Message $message)
    {
        $requestBody = array_merge(['cmd' => '_notify-validate'], $message->getAll());
        try {
            $response = $this->httpClient->post($this->serviceEndpoint, array('form_params' => $requestBody));
        } catch (\Exception $e) {
            throw new ServiceException($e->getMessage());
        }
        return new ServiceResponse((string) $response->getBody());
    }