public void FjerneBilenFraParkeringspladsen_Ved_ForladPladsen() { var regNr = "12345678"; var car = A.Fake <ICar>(); var parkingLot = A.Fake <IParkingLot>(); A.CallTo(() => car.RegistrationNumber).Returns(regNr); A.CallTo(() => parkingLot.Cars).Returns(new List <ICar> { car }); var sut = new ParkingLotService(parkingLot); sut.Leave(car); Assert.DoesNotContain(parkingLot.Cars, a => a.RegistrationNumber == regNr); }