nasty.cs

public class MyBackgroundService : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        using var disposer = messageQueue.Subscribe(async (msg) =>
        {
            await ProcessMessageAsync(msg, stoppingToken);
        });

        // Nasty!
        while (!stoppingToken.IsCancellationRequested)
        {
            await Task.Delay(1000000, stoppingToken);
        }
    }
}