public async void CountdownTaskSchedulerShouldTrackExternalTaskExecution()
        {
            var task = new Task(() => _isStopped = true, TaskCreationOptions.LongRunning);

            _countdownTaskScheduler.TrackTaskExecution(task);

            task.Start(TaskScheduler.Default);

            await _countdownTaskScheduler.WaitAsync();

            Assert.True(_isStopped);
        }