I feel bad for nitpicking contributions, but I worry that the description of the method is not entirely accurate. In particular, we don't mention `Task`s at all. I understand `valueProducer`'s role in creating the desired return value, but it doesn't _quite_ produce the return value.
We may also benefit from mentioning that the Task that's returned will already be completed, and what users should do if they want to fake out a non-completed Task.
Really, a lot of these comments also apply to the `Returns` documentation. I'd've preferred to comment then, but I was travelling and didn't have the opportunity to examine the original implementation.