Github user GJL commented on the issue:
https://github.com/apache/flink/pull/5305
Thanks for your contribution, @nicktoker. Unfortunately with your pull
request you are trying to merge the `release-1.3` branch into the `master`. You
probably want to create a feature branch from a release or the master first and
then target your pull request to the specific release. Also make sure that for
non-trivial changes, there is a JIRA ticket. For more information, see the
contribution guidelines: http://flink.apache.org/contribute-code.html
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