Sharekhan.domain.ShortTermTaxCalculator.CreateSellTransactionStack C# (CSharp) Method

        public virtual Stack CreateSellTransactionStack()
        {
            Stack sellStack = new Stack();

            for (int i = Transactions.Count - 1; i >= 0; i--)
            {
                if (Transactions[i].GetType() == typeof(SellTransaction))
                {
                    sellStack.Push(Transactions[i]);

                }

            }
            return sellStack;
        }

        public void ShouldBeAbleToCalculateTaxGivenABuyStackAndSellStackWithMultipleValues()
        {
            Instrument share = new Stock(new Symbol("REL"), new Price(10.00), "Rel*iance Power");
            Transaction buyTransaction1 = new BuyTransaction(new DateTime(2008, 06, 01), share, 20, new Price(10.00), 5.00, 3.00);
            Transaction sellTransaction1 = new SellTransaction(new DateTime(2009, 01, 01), share, 10, new Price(20.00), 5.00, 3.00);
            Transaction buyTransaction2 = new BuyTransaction(new DateTime(2008, 12, 01), share, 10, new Price(10.00), 5.00, 3.00);
            Transaction sellTransaction2 = new SellTransaction(new DateTime(2009, 08, 01), share, 10, new Price(20.00), 5.00, 3.00);

            List<Transaction> listTransaction = new List<Transaction> { buyTransaction1, sellTransaction1, buyTransaction2, sellTransaction2 };

            ShortTermTaxCalculator TaxCalculator = new ShortTermTaxCalculator(listTransaction, new FinYear(2009));

            Stack buyStack = TaxCalculator.CreateBuyTransactionStack();
            Stack sellStack = TaxCalculator.CreateSellTransactionStack();

            Assert.AreEqual(2, buyStack.Count);
            Assert.AreEqual(2, sellStack.Count);

            Price Tax;
            Tax = TaxCalculator.CalculateTaxOverTheBuyAndSellStacks(buyStack, sellStack);

            //            Assert.AreEqual(0, buyStack.Count);
            //            Assert.AreEqual(0, sellStack.Count);

            Assert.AreEqual(20, Tax.Value);
        }