using System;

using System.Data;

using System.Data.SqlClient;

using System.Diagnostics;

using System.Threading.Tasks;

using System.Collections.Generic;

using System.Linq;

using System.IO;

​

class ChainMethodClass

{

    public async Task<ChainMethodClass> Method1()

    {

        await Task.FromResult(0);

        return this;

    }

    public async Task<ChainMethodClass> Method2()

    {

        await Task.FromResult(0);

        return this;

    }

    public async Task<ChainMethodClass> Method3()

    {

        await Task.FromResult(0);

        return this;

    }

}

public class Program

{

    public static async Task Main()

    {

        var chainMethodClass = new ChainMethodClass();

​

        // Works

        await chainMethodClass.Method1();

        await chainMethodClass.Method2();

        await chainMethodClass.Method3();

​

        // Doesn't.

        await chainMethodClass

            .Method1()

            .Method2()

            .Method3();

    }

}