public void BuilderTest()
        {
            VehicleBuilder builder = new VehicleBuilder();
            Vehicle        vehicle = builder.AddLicensePlate("Lic")
                                     .AddMark("mark")
                                     .ToVehicle();

            Assert.AreEqual("Lic", vehicle.LicensePlate);
            Assert.AreEqual("mark", vehicle.Mark);
        }