using System;

using System.Threading.Tasks;

using System.Threading;

​

public class Program

{

    public async static void Main()

    {

        Console.WriteLine("Hello World");

        var tester = new TestMe();

        var source = new CancellationTokenSource();

        await Task.Run(async () =>{

            await tester.TestCancel(source.Token);  

            Thread.Sleep(10000);

            source.Cancel();

        });

    }

}

​

public class TestMe 

{

​

    public async Task TestCancel(CancellationToken cancellationToken){

        Console.WriteLine("before cancel is requested handled");

        await Task.Delay(-1, cancellationToken);

        Console.WriteLine("cancel is requested");

    }

}