public void CanApplyTeaSpecialOfferToTwoOfEachItemShoppingTrolley_ShouldReturn35_57() { var checkout = new Checkout(_twoOfEachItemShoppingTrolley); var discountedTrolley = checkout.ApplyTeaSpecialOffer(); var discountedTotal = checkout.GetTotal(); Assert.AreNotEqual(discountedTrolley, null); Assert.AreEqual(discountedTrolley.Count(), 6); Assert.AreEqual(discountedTotal, 35.57); }