Github user liurenjie1024 commented on the issue:
https://github.com/apache/flink/pull/5680
@bowenli86 @fhueske UT added.
This class is a utility class which can be the base class of many process
function implementations in flink table. Its counterpart for the legacy
`ProcessFunction `interface, `ProcessFunctionWithCleanupState`, has been
inherited by many implementations. In fact, my other
[PR](https://github.com/apache/flink/pull/5688) depends on this.---
