static void Main(string[] args) { var espresso = new Espresso(); Console.WriteLine($"{espresso.AsString()} costs {espresso.Cost()} $"); var espressoWithMilk = new WithMilk(espresso); Console.WriteLine($"{espressoWithMilk.AsString()} costs {espressoWithMilk.Cost()} $"); var espressoWithMilkAndSugar = new WithSugar(espressoWithMilk); Console.WriteLine($"{espressoWithMilkAndSugar.AsString()} costs {espressoWithMilkAndSugar.Cost()} $"); Console.ReadKey(); }