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
}