public void Parking_IsSingelton() { var newParkingService = new ParkingService(_withdrawTimer, _logTimer, _logService); var vehicle = new Vehicle("AA-0001-AA", VehicleType.Truck, 100); _parkingService.AddVehicle(vehicle); Assert.Single(newParkingService.GetVehicles()); Assert.Single(_parkingService.GetVehicles()); Assert.Same(_parkingService.GetVehicles()[0], newParkingService.GetVehicles()[0]); }