public void NonApplesAreTheSamePrice()
        {
            var offer   = new AppleTenPercentDiscountOffer();
            var success = offer.TryApplyDiscount(new[] { Mango() }, out var discount);

            success.Should().BeFalse();
        }
        public void MultipleApplesAreTenPercentOff()
        {
            var offer   = new AppleTenPercentDiscountOffer();
            var success = offer.TryApplyDiscount(new[] { Apple(), Apple(), Apple() }, out var discount);

            success.Should().BeTrue();
            discount.BaseAmount.Should().Be(applePrice * 0.1m);
            discount.TimesApplied.Should().Be(3);
        }