public void ApplyTotalDiscountRule_ValidDiscount(int numDevices, decimal amount,
                                                         decimal expectedDiscount)
        {
            decimal discount = DiscountHelper.ApplyTotalDiscountRule(numDevices, amount);

            Assert.Equal(expectedDiscount, discount);
        }
        public void ApplyTotalDiscountRule_NoDiscount(int numDevices, decimal amount)
        {
            decimal discount = DiscountHelper.ApplyTotalDiscountRule(numDevices, amount);

            Assert.Equal(0.0m, discount);
        }