public void Task_Booking_CheckOut()
        {
            //Arrange
            var controller = new BookingController(context);
            int CustomerId = 57;

            //Act
            Assert.Throws <NullReferenceException>(() =>
            {
                var data = controller.Checkout(CustomerId);
                //Assert
                Assert.IsType <RedirectToActionResult>(data);
            });
        }