Github user StephanEwen commented on the issue:
https://github.com/apache/flink/pull/3633
I finally found the time to look at this.
Have rebased it and applied some simplifications:
- convenience constructors for stateless tasks
- test utils that provide mock environments directly
- Task Test Harnesses create the tasks lazily via a factory.
All in all that makes for a good patch in my opinion.
Will merge this...---
