static void Main(string[] args) { IBM ibm = new IBM("IBM", 120.0); ibm.Attach(new Investor("Sorros")); ibm.Attach(new Investor("Berkshire")); // Change price, which notifies investors ibm.Price = 120.10; ibm.Price = 121.00; ibm.Price = 120.50; ibm.Price = 120.75; // Wait for user Console.Read(); }