using System;

using System.Collections.Generic;

using System.Reactive.Disposables;

using System.Reactive.Linq;

using System.Threading.Tasks;

using Microsoft.Reactive.Testing;

using System.Reactive.Subjects;

public class Program

{

    protected static event EventHandler<EventArgs> CancelEvent;

​

    public static async void Main()

    {

​

​

            var x = new ReplaySubject<int>(1);

            x.OnNext(42);

            var val = await x.Take(1).LastAsync();

            Console.WriteLine("val");

            Console.WriteLine(val);

            x.Subscribe(e => {Console.WriteLine("next ");Console.WriteLine(e);});

    }

}