using System;

public interface IFrob {

  String frob();

}

​

class Test /* implements IFrob */ {

  public String frob() {

    return "Test";

  }

}

​

​

public class Program

{

  public static void frob(IFrob frobbable) {

    Console.WriteLine(frobbable.frob());

  }

    public static void Main()

    {

        frob(new Test());

    }

}