[jira] (FLINK-2883) Add documentation to forbid key-modifying ReduceFunction

[Robert Metzger (JIRA)]

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Robert Metzger updated an issue   Flink / FLINK-2883 Add documentation to forbid key-modifying ReduceFunction Change By: Robert Metzger Component/s: DataStream API Add Comment   This message was sent by Atlassian JIRA (v6.3.15#6346-sha1:dbc023d)