Github user yanghua commented on the issue:
https://github.com/apache/flink/pull/6229
Hi @satybald thanks for your contribution, based on [Flink's contribution
guide](http://flink.apache.org/how-to-contribute.html) you'd better open an
issue in
[JIRA](https://issues.apache.org/jira/projects/FLINK/issues/FLINK-8785?filter=allopenissues)
before submit a PR.---
