code: public function subscribeAction(AvailabilityAlertSubscriptionRequestTransfer $availabilityAlertSubscriptionRequestTransfer)
      {
          $availabilityAlertSubscriptionTransfer = $this->getFactory()
              ->createAvailabilityAlertSubscriptionSubmitMapper()
              ->mapRequestTransfer($availabilityAlertSubscriptionRequestTransfer);
  
          return $this->getFacade()->subscribe($availabilityAlertSubscriptionTransfer);
      }
docs: @param \Generated\Shared\Transfer\AvailabilityAlertSubscriptionRequestTransfer $availabilityAlertSubscriptionRequestTransfer
  
  @return \Generated\Shared\Transfer\AvailabilityAlertSubscriptionResponseTransfer