rg/jira/browse/FLINK-3835">FLINK-3835</a>] [optimizer] Add input id to JSON plan to resolve ambiguous input names</li>
<li>[hotfix] OptionSerializer.duplicate to respect stateful element serializer</li>
<li>[<a href="https://issues.apache.org/jira/browse/FLINK-3803">FLINK-3803</a>] [runtime] Pass CheckpointStatsTracker to ExecutionGraph</li>
<li>[hotfix] [cep] Make cep window border treatment consistent</li>
</ul>
<h3 id="improvement">
  Improvement
  <a class="anchor" href="#improvement">#</a>
</h3>
<ul>
<