private IEnumerable<RaceControl<string>> _testAsync(Race<string> race)
{
5.Log("Wait anywhere");
Thread.Sleep(5);
yield return race.RunAsync("a", () =>
{
5.Log("Wait in a?");
Thread.Sleep(10);
});
yield return race.RunAs("b");
10.Log("Wait in b?");
Thread.Sleep(5);
}