using System;

using System.Threading;

using System.Threading.Tasks;

#nullable enable

public class Program

{

    public static Timer CreateTimer(TimerCallback cb, AutoResetEvent autoResetEvent)

    {

        return new Timer(cb, autoResetEvent, 1000, 250);

    }

    public static void Main()

    {

        var autoResetEvent = new AutoResetEvent(false);

        var timer = CreateTimer(OnTimeout, autoResetEvent);

        autoResetEvent.WaitOne();

        Thread.Sleep(TimeSpan.FromSeconds(1));

    }

    public static async void OnTimeout(object? state)

    {

        if (state is AutoResetEvent are)

        {

            await Task.Run(() => are.Set());

            Console.WriteLine("Signaled completion");

        }

    }

}

#nullable restore