public function callbackAction()
    {
        try {
            $response = $this->getPaymentHandler()->getPaymentCallbackResponse($this->getCurrentRequest());
        } catch (EntityNotFoundException $ex) {
            throw new NotFoundHttpException($ex->getMessage());
        } catch (InvalidTransactionException $ex) {
            throw new UnauthorizedHttpException($ex->getMessage());
        }

        return $response;
    }