public void reversePaymentTest()
        {
            ECommerceClient client = new ECommerceClient(CARD_ACCEPTOR, SHARED_SECRET, TEST_ENVIRONMENT);
            Payment payment = client.payment(CURRENCY_ISK, AMOUNT_70_APPROVE_AMOUNT, VISA_TEST_CARD, EXPIRY_DATE_DECEMBER_2015);
            Reversal reversal = client.reversePayment(payment.PaymentGuid);

            Assert.IsNotNull(reversal.ReversalGuid);
            Assert.AreEqual(payment.PaymentGuid, reversal.PaymentGuid);
            Assert.IsNotNull(reversal.ApprovalCode);
        }
 public void cancelPaymentTest()
 {
     ECommerceClient client = new ECommerceClient(CARD_ACCEPTOR, SHARED_SECRET, TEST_ENVIRONMENT);
     Payment payment = client.payment(CURRENCY_ISK, AMOUNT_70_APPROVE_AMOUNT, VISA_TEST_CARD, EXPIRY_DATE_DECEMBER_2015);
     Assert.IsNotNull(payment.PaymentGuid);
     Assert.IsNotNull(payment.ApprovalCode);
     Cancellation cancellation = client.cancelPayment(CURRENCY_ISK, AMOUNT_70_APPROVE_AMOUNT, payment.TerminalDateTime);
     Assert.IsNotNull(cancellation.CancellationGuid);
     Assert.IsNotNull(cancellation.PaymentGuid);
     Assert.IsNotNull(cancellation.ApprovalCode);
 }