human
Here's a good function header given the following:
I wrote the below code

    (worker, doer) = createMemoryWorker()
    class CFT(object, ):
        def callFromThread(self, f, *a, **k):
            worker.do((lambda : f(*a, **k)))
    return (CFT(), doer)

What's a good function header?
assistant
#Here's a good function header.

def deterministicReactorThreads():