Github user yew1eb commented on the issue:
https://github.com/apache/flink/pull/4777
@pnowojski
Multiple commits may refer to the same issue, if the issue is fixed in
multiple steps.
```
[FLINK-1234] [runtime] Runtime support some cool new thing
[FLINK-1234] [java api] Add hook for cool thing to java api
[FLINK-1234] [scala api] Add hook for that thing to scala api
[FLINK-1234] [optimizer] Make optimizer aware that it can exploit this thing
```
from [Apache Flink development
guidelines](https://cwiki.apache.org/confluence/display/FLINK/Apache+Flink+development+guidelines).
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