Github user tzulitai commented on the issue:
https://github.com/apache/flink/pull/5952
Would filtering the thread count by thread name be helpful here?
Another possible approach to test this:
Maybe we can simply verify that the current transaction producer is closed
after the cleanup?
This would require making the `getCurrentTransaction()` method visible for
tests, though. We'll also need to have a `isClosed()` method on the
`FlinkKafkaProducer`.---
