using System;

public class Program

{

static void Main(string[] args)

        {

            MethodA().Wait();

        }

        private static async Task MethodA()

        {

            Console.WriteLine($"MethodA before. ThreadId {Thread.CurrentThread.ManagedThreadId}");

​

            await MethodB();

​

            Console.WriteLine($"MethodA after. ThreadId {Thread.CurrentThread.ManagedThreadId}");

        }

​

        private static async Task MethodB()

        {

            Console.WriteLine($"MethodB before. ThreadId {Thread.CurrentThread.ManagedThreadId}");

​

            await Task.Delay(100);

​

            Console.WriteLine($"MethodB after. ThreadId {Thread.CurrentThread.ManagedThreadId}");

        }

}