public void ReturnSixDollars_WhenPurchasing_TwoPikachu()
        {
            var toysToPurchase = new string[8] {
                "Pikachu", "Squirtle", "Pikachu", "Squirtle", "Pikachu", "Squirtle", "Pikachu", "Squirtle"
            };
            var bill = PokemonCashRegister.CalculateBill(toysToPurchase);

            bill.ShouldBeEquivalentTo(38.40);
        }
        public void ReturnSixDollars_WhenPurchasing_OnePikachu()
        {
            var toysToPurchase = new string[1] {
                "Pikachu"
            };
            var bill = PokemonCashRegister.CalculateBill(toysToPurchase);

            bill.ShouldBeEquivalentTo(6);
        }