public void GetDiscount_WhenCalledForAmountCoupon_ReturnsDiscount()
{
//Arrange
CouponFactory factory = new CouponFactory();
AmountCoupon coupon = factory.ProduceCoupon(50, 10, DiscountType.Amount) as AmountCoupon;
//Act
double discount = coupon.GetDiscount(120);
//Assert
Assert.Equal(coupon.Discount, discount);
}
