code: public function listInboundShipmentItems($request)
      {
          if (!($request instanceof FBAInboundServiceMWS_Model_ListInboundShipmentItemsRequest)) {
              $request = new FBAInboundServiceMWS_Model_ListInboundShipmentItemsRequest($request);
          }
          $parameters = $request->toQueryParameterArray();
          $parameters['Action'] = 'ListInboundShipmentItems';
          $httpResponse = $this->_invoke($parameters);
  
          $response = FBAInboundServiceMWS_Model_ListInboundShipmentItemsResponse::fromXML($httpResponse['ResponseBody']);
          $response->setResponseHeaderMetadata($httpResponse['ResponseHeaderMetadata']);
          return $response;
      }
docs: List Inbound Shipment Items
  Gets the first set of inbound shipment items for the given ShipmentId or
  all inbound shipment items updated between the given date range.
  A NextToken is also returned to further iterate through the Seller's
  remaining inbound shipment items. To get the next set of inbound
  shipment items, you must call ListInboundShipmentItemsByNextToken and
  pass in the 'NextToken' this call returned. If a NextToken is not
  returned, it indicates the end-of-data. Use LastUpdatedBefore
  and LastUpdatedAfter to filter results based on last updated time.
  Either the ShipmentId or a pair of LastUpdatedBefore and LastUpdatedAfter
  must be passed in. if ShipmentId is set, the LastUpdatedBefore and
  LastUpdatedAfter will be ignored.
  
  @param mixed $request array of parameters for FBAInboundServiceMWS_Model_ListInboundShipmentItems request or FBAInboundServiceMWS_Model_ListInboundShipmentItems object itself
  @see FBAInboundServiceMWS_Model_ListInboundShipmentItemsRequest
  @return FBAInboundServiceMWS_Model_ListInboundShipmentItemsResponse
  
  @throws FBAInboundServiceMWS_Exception