private static void RentalAdded() { RentalManager rentalManager = new RentalManager(new EfRentalDal()); var result = rentalManager.Added(new Rental { RentalId = 4, CarId = 1, CustomerId = 4, RentDate = new DateTime(2020, 12, 03), ReturnDate = null }); Console.WriteLine(result.Message); }