def on_change_shipment(self):
        <...>

        result = {
            'shipment': None,
            'line_moves': []
        }

        result['line_moves'].append(('create',
                    [{'stock_move': stock_move.id, 'landed_cost': True}
                      for stock_move in shipment.incoming_moves if stock_move.id not in stock_moves_ids]))

        return result