code: public function listInboundShipmentsByNextToken($request)
      {
          if (!($request instanceof FBAInboundServiceMWS_Model_ListInboundShipmentsByNextTokenRequest)) {
              $request = new FBAInboundServiceMWS_Model_ListInboundShipmentsByNextTokenRequest($request);
          }
          $parameters = $request->toQueryParameterArray();
          $parameters['Action'] = 'ListInboundShipmentsByNextToken';
          $httpResponse = $this->_invoke($parameters);
  
          $response = FBAInboundServiceMWS_Model_ListInboundShipmentsByNextTokenResponse::fromXML($httpResponse['ResponseBody']);
          $response->setResponseHeaderMetadata($httpResponse['ResponseHeaderMetadata']);
          return $response;
      }
docs: List Inbound Shipments By Next Token
  Gets the next set of inbound shipments created by a Seller with the
  NextToken which can be used to iterate through the remaining inbound
  shipments. If a NextToken is not returned, it indicates the end-of-data.
  
  @param mixed $request array of parameters for FBAInboundServiceMWS_Model_ListInboundShipmentsByNextToken request or FBAInboundServiceMWS_Model_ListInboundShipmentsByNextToken object itself
  @see FBAInboundServiceMWS_Model_ListInboundShipmentsByNextTokenRequest
  @return FBAInboundServiceMWS_Model_ListInboundShipmentsByNextTokenResponse
  
  @throws FBAInboundServiceMWS_Exception