Github user tzulitai commented on the issue:
https://github.com/apache/flink/pull/5364
@aljoscha @zentol
could you have another quick look at commit 8882fb7? That commit extends
`KeyedComplexChainTest`, `ChainBreakTest`, `ChainLengthIncreaseTest`, ... etc.
also for 1.4.
Once that is good, I'll merge this to `master` and `release-1.4`.---
