var stringLocal = new AsyncLocal<string>();

async IAsyncEnumerable<int> IntSequence()
{
    stringLocal.Value = "Test";
    yield return 10;
    // Now what should happen if we do not explicitly capture the execution context???
    Console.WriteLine("stringLocal.Value: {0}", stringLocal.Value);
}

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

var stringLocal = new AsyncLocal<string>();

async IAsyncEnumerable<int> IntSequence(string localValue)
{
    stringLocal.Value = localValue;
    Console.WriteLine("Set up stringLocal: {0}.", localValue);
    await Task.Delay(100).ConfigureAwait(false);
    // await didn't affect AsyncLocal flow
    Console.WriteLine("stringLocal.Value: {0}", stringLocal.Value);

    using var execContext = ExecutionContext.Capture();
    Debug.Assert(execContext != null);      // i.e. ExecutionContext.IsFlowSuppressed() == false
    yield return 10;
    ExecutionContext.Restore(execContext);
    // This gives us the correct value, as we have restored execution context.
    Console.WriteLine("stringLocal.Value: {0}", stringLocal.Value);

    // Now what should happen if we do not explicitly capture the execution context???
    yield return 20;
    Console.WriteLine("stringLocal.Value: {0}", stringLocal.Value);
    yield return 30;
    Console.WriteLine("stringLocal.Value: {0}", stringLocal.Value);
}

async Task PrintSequence1()
{
    await foreach (var i in IntSequence("value 1"))
    {
        Console.WriteLine("Sequence: {0}", i);
        await Task.Delay(100);
    }
}

async Task PrintSequence2()
{
    await using var it = IntSequence("value 2").GetAsyncEnumerator();
    while (await it.MoveNextAsync())
    {
        Console.WriteLine("Sequence: {0}", it.Current);
    }
}

PrintSequence1().Wait();
Console.WriteLine();
PrintSequence2().Wait();