code: public function execute($request)
      {
          if (!$this->supports($request)) {
              throw RequestNotSupportedException::createActionNotSupported($this, $request);
          }
  
          /** @var $payment PaymentInterface */
          $payment = $request->getModel();
  
          $this->payment->execute(new Sync($payment));
  
          $status = new GetStatus($payment);
          $this->payment->execute($status);
  
          $nextState = $status->getValue();
  
          $this->updatePaymentState($payment, $nextState);
  
          $this->objectManager->flush();
      }
docs: {@inheritDoc}
  
  @param $request Notify