ReactiveX/RxJava — pull request #1774 by akarnokd (2014-10-17 11:57:00+00:00)
Title: Serialized backpressure support proposal.

It took me a while to get it working and I'm not sure what tests to write to check backpressure behavior besides the request 5s from a sequence of 15.

In addition, it was a bit confusing when to call onStart, what exactly the setProducer call supposed to do and what to do when noone calls setProducer from upstream.