code: public function listInboundShipmentItemsByNextToken($request)
      {
          if (!($request instanceof FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextTokenRequest)) {
              $request = new FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextTokenRequest($request);
          }
          $parameters = $request->toQueryParameterArray();
          $parameters['Action'] = 'ListInboundShipmentItemsByNextToken';
          $httpResponse = $this->_invoke($parameters);
  
          $response = FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextTokenResponse::fromXML($httpResponse['ResponseBody']);
          $response->setResponseHeaderMetadata($httpResponse['ResponseHeaderMetadata']);
          return $response;
      }
docs: List Inbound Shipment Items By Next Token
  Gets the next set of inbound shipment items with the NextToken
  which can be used to iterate through the remaining inbound shipment
  items. If a NextToken is not returned, it indicates the end-of-data.
  You must first call ListInboundShipmentItems to get a 'NextToken'.
  
  @param mixed $request array of parameters for FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextToken request or FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextToken object itself
  @see FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextTokenRequest
  @return FBAInboundServiceMWS_Model_ListInboundShipmentItemsByNextTokenResponse
  
  @throws FBAInboundServiceMWS_Exception