code: public function getSubscription($request)
      {
          if (!($request instanceof MWSSubscriptionsService_Model_GetSubscriptionInput)) {
              require_once (dirname(__FILE__) . '/Model/GetSubscriptionInput.php');
              $request = new MWSSubscriptionsService_Model_GetSubscriptionInput($request);
          }
          $parameters = $request->toQueryParameterArray();
          $parameters['Action'] = 'GetSubscription';
          $httpResponse = $this->_invoke($parameters);
  
          require_once (dirname(__FILE__) . '/Model/GetSubscriptionResponse.php');
          $response = MWSSubscriptionsService_Model_GetSubscriptionResponse::fromXML($httpResponse['ResponseBody']);
          $response->setResponseHeaderMetadata($httpResponse['ResponseHeaderMetadata']);
          return $response;
      }
docs: Get Subscription
  Retrieve subscription information.
  
  @param mixed $request array of parameters for MWSSubscriptionsService_Model_GetSubscription request or MWSSubscriptionsService_Model_GetSubscription object itself
  @see MWSSubscriptionsService_Model_GetSubscriptionInput
  @return MWSSubscriptionsService_Model_GetSubscriptionResponse
  
  @throws MWSSubscriptionsService_Exception