public async Task GenerateProductSlipTest()
        {
            try
            {
                var     controller = new PaymentController();
                Payment payment    = new Payment {
                    PaymentOptionId = 1, IsPaid = true, Status = 'P', PaidDate = DateTime.Now, PaidAmount = 200
                };
                SlipDeatils slipDeatils = new SlipDeatils {
                    SlipAddress = "aaa", ContactNumber = "2233"
                };
                int moduleId = 1;
                var result   = await controller.GenerateProductSlip(moduleId, payment, slipDeatils);

                Assert.Equal(result.Value, true);
                Assert.NotEqual(result.Value, true);
            }
            catch (Exception ex)
            {
                Assert.NotNull(ex);
            }
        }