public void SellInvestment()
        {
            // Arrange
            StockEngine engine = new YahooStockEngine();
            IEnumerable<Quote> stocks = engine.AllQuotes();

            Investment investment = new Investment() { Id = Guid.NewGuid() };
            decimal newPrice = 1.1m;

            // Act
            engine.SellInvestment(investment.Id, newPrice, SellReason.HighPrice, DateTime.Today);

            // Assert
        }