using System; class MainClass { static void Main() { A a = new A(); a.Value = new A(); Console.WriteLine("{0}", a?.DoIt()?.DoIt()?.DoIt()); Console.WriteLine("Hello World!"); } } public class A { public A Value {get;set;} } public static class AExtensions { public static A DoIt(this A a) { Console.WriteLine("IN IT, {0}, returning {1}", a == null ? "NULL A" : "NOT-NULL A", a.Value == null ? "NULL A" : "NOT-NULL A"); return a.Value; } }