using System;
public class Program
{
public static void Main()
var a = new A1();
a.m1();
a.m2();
var a2 = new A2();
a2.m3();
a2.m4();
}
public static class ExtensoesA1
public static void Baka(this A1 a1)
Console.WriteLine("I work");
public class A1
public void m1()
this.Baka();
public void m2()
Baka();
public class A2 : A1
public void m3()
public void m4()