using System;

using System.Collections.Generic;                   

​

public class Program

{

    public class EventTest

    {

        private event Action<int> events;

        private Action<int> delegates;

        public void AttachEvent(Action<int> ev)

        {

            events += ev;

        }

        public void AttachDelegate(Action<int> del)

        {

            delegates += del;

        }

        public void RaiseEvents(int on)

        {

            events.Invoke(on);

        }

        public void RaiseDelegates(int on)

        {

            delegates.Invoke(on);

        }

    }

    static public class BullshitUtility

    {

        public static void InvokeFirst(int on)

        {

            Console.WriteLine("This is first on {0}", on);

        }

        public static void InvokeSecond(int on)

        {

            Console.WriteLine("This is second on {0}", on);

        }

    }

    public static void Main()

    {

        var et = new EventTest();

        et.AttachEvent(BullshitUtility.InvokeFirst);

        et.AttachEvent(BullshitUtility.InvokeSecond);

        et.RaiseEvents(10);

        et.AttachDelegate(BullshitUtility.InvokeFirst);

        et.AttachDelegate(BullshitUtility.InvokeSecond);

        et.RaiseDelegates(20);

    }

}