using System; public interface IPrintMessage { void Print(); }; class Class1 { public void Print() { Console.WriteLine("Hello from Class1!"); } } class Class2 : IPrintMessage { public void Print() { Console.WriteLine("Hello from Class2!"); } } class MainClass { public static void Main() { PrintClass PrintObject = new PrintClass(); PrintObject.PrintMessages(); } } class PrintClass { public void PrintMessages() { Class1 Object1 = new Class1(); Class2 Object2 = new Class2(); PrintMessageFromObject(Object1); PrintMessageFromObject(Object2); } private void PrintMessageFromObject(object obj) { if(obj is IPrintMessage) { IPrintMessage PrintMessage; PrintMessage = (IPrintMessage)obj; PrintMessage.Print(); } } }