using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        List<INotifier> bar = new List<INotifier>();

        INotifier x = new Notifier1();

        INotifier y = new Notifier2();

        bar.Add(x);

        bar.Add(y);

        Controller foo = new Controller(bar);

        foo.Action();

    }

}

​

public class Controller

{

    private IEnumerable<INotifier> _notifiers;

    public Controller(IEnumerable<INotifier> notifiers)

    {

        this._notifiers = notifiers;

    }

    public string Action()

    {

        _notifiers.ToList().ForEach(x => x.Notify());

        return "Complete";

    }

}

​

public interface INotifier

{

    void Notify();

}

public class Notifier1 : INotifier

{

    public void Notify()

    {

        Console.WriteLine("Debugging from Notifier 1");

    }

}

public class Notifier2 : INotifier

{

    public void Notify()

    {

        Console.WriteLine("Debugging from Notifier 2");

    }

}