using System;

public class Program

{

    public class Notifier{      

        public delegate void Del(int portfolioId);

        private static Del _listeners;

        public static void register(Del listener){

            _listeners += listener;

        }

        private void notify(int thingThatHappened){

            _listeners(thingThatHappened);

        }

        public void SavePortfolioElt(int portfolioId){

            Console.WriteLine($"Accumulation Completed for Portfolio[{portfolioId}]");

            notify(portfolioId);

        }

    };

    public class OnDemandManager{

        public OnDemandManager(){

            Notifier.register(this.NewPortfolio);

        }

        public void NewPortfolio(int portfolioId){

            Console.WriteLine($"OnDemandManager: Just go notified a new Portfolio {portfolioId} is available");

        }

    }

    public class AnotherManager{

        public AnotherManager(Notifier n)

        {

            Notifier.register(NewPortfolio);

        }

        public void NewPortfolio(int portfolioId){

            Console.WriteLine($"AnotherManager: Just go notified a new Portfolio {portfolioId} is available");

        }

​

    }

    public static void Main()

    {

        var notifier = new Notifier();

        var listener1 = new OnDemandManager();

        var listener2 = new AnotherManager(notifier);

        notifier.SavePortfolioElt(40899);

        Console.WriteLine("Hello World");

    }

}