/// <summary>
/// Wait until all tasks have been completed. NOTE that this will do a pumping wait if
/// called on the UI thread. Also, it isn't guaranteed to be stable in the case of tasks
/// enqueuing other tasks in arbitrary orders, though it does support our common pattern of
/// "timer task->background task->foreground task with results"
///
/// Use this method very judiciously. Most of the time, we should be able to just use
/// IAsynchronousOperationListener for tests.
/// </summary>
public void WaitUntilCompletion()
{
_asynchronousSerialWorkQueue.AssertIsForeground();
_asynchronousSerialWorkQueue.WaitForPendingBackgroundWork();
}