public void Task_Booking_Buy()
        {
            //Arrange
            var controller = new BookingController(context);

            int BookingId = 117;

            //Act
            Assert.Throws <NullReferenceException>(() =>
            {
                IActionResult data = controller.Buy(BookingId);
                //Assert
                Assert.IsType <RedirectToActionResult>(data);
            });
        }