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So it's really pretty > inconsistent IMO. Yes it is going to act in ways that look non-deterministic. And that's OK, because: a) It's not broken. b) It's not unreasonable nor even terribly surprising behavior: one can reason about it. c) The requested behavior itself is impossible: "do X for an infinitely short amount of time". Why are we adding code to optimize behavior for callers that should not even exist? thanks, -- John Hubbard