private static void RentalManagerTest() { RentalManager rentalManager = new RentalManager(new EfRentalDal()); var result = rentalManager.GetRentalByCarId(1); bool isAvailableCar = rentalManager.CarIsAvailable(result.Data); if (isAvailableCar) { rentalManager.Add(new Rental { CarId = 1, CustomerId = 1, RentDate = DateTime.Now, ReturnDate = (DateTime)System.Data.SqlTypes.SqlDateTime.Null }); } else { Console.WriteLine(result.Data.CarId + " Car is not Available "); } }