public void Test_open_should_return_total_stocks_quantity() { StockHistory history = new StockHistory(); Quote quote = new Quote(2, 4); Broker broker = new Broker(50); Investment investment = new Investment(history, broker); DateTime openDate = new DateTime(2020, 2, 10); DateTime closeDate = new DateTime(2020, 4, 10); DateTime februaryBuyDate = new DateTime(2020, 2, 28); DateTime marchBuyDate = new DateTime(2020, 3, 27); double stocksQuantity = 10; double amount = 20; history.Add(februaryBuyDate, quote); history.Add(marchBuyDate, quote); Assert.AreEqual(stocksQuantity, investment.Open(openDate, closeDate, amount)); }