using System;

using System.Threading.Tasks;

​

class ExampleIncorrectlyStackedProgram

{

    static async Task A() // Main()

    {

        var objOne = new ThrowingAsyncDisposable("1", throwEx: true);

        var objTwo = new ThrowingAsyncDisposable("2", throwEx: false);

        await using (objOne.ConfigureAwait(false))

        await using (objTwo.ConfigureAwait(false))

        {

        }

​

        Console.ReadLine();

    }

    static async Task Main() // B()

    {

        var objOne = new ThrowingAsyncDisposable("1", throwEx: true);

        await using (objOne.ConfigureAwait(false))

        {

        }

        var objTwo = new ThrowingAsyncDisposable("2", throwEx: false);

        await using (objTwo.ConfigureAwait(false))

        {

        }

​

        Console.ReadLine();

    }

}

​

public class ThrowingAsyncDisposable : IAsyncDisposable

{

    readonly string _instanceName;

    readonly bool _throwEx;

​

    public ThrowingAsyncDisposable(

        string instanceName, bool throwEx = false) =>

        (_instanceName, _throwEx) = (instanceName, throwEx);

​

    public async ValueTask DisposeAsync()

    {

        if (_throwEx)

        {

            throw new Exception("Oops...");

        }

​

        await new ValueTask();

​

        Console.WriteLine($"Successfully awaited {_instanceName} async disposable.");

    }

}