public void PriceVisitor_TraverseEquipment_CollectTotalPrice()
        {
            var visitor = new PriceVisitor(3);

            foreach (var e in _equipments)
            {
                e.Accept(visitor);
            }

            _output.WriteLine($"total price is: {visitor.TotalPrice()}");
            //the visitor in its current impl takes net price of equipment and there are 4 instances in the list => 4*100
            visitor.TotalPrice().Should().BeGreaterThan(400);

            visitor.Reset();
            _bus.Accept(visitor);

            _output.WriteLine($"bus and its devices price is: {visitor.TotalPrice()}");
        }