private void SendEmailPurchaseDescription(PromoCode promoCode)
        {
            string message = string.Format("You won a discount of ${0} on your next purchase",
                                           promoCode.DiscountValue.ToString("#0.00"));

            return;
        }
        public Guid Process()
        {
            this.Pay();
            PromoCode promoCode = PromoCode.Create(this.Order.Customer, 10);

            SendEmailPurchaseDescription(promoCode);

            return(this.AuthorizationNumber);
        }