[FLINK-18406] Annotate DualKeyLinkedMap with @Nullable annotation

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.11.0, 1.12.0
• Fix Version/s: 1.12.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Till Rohrmann
• Reporter: Till Rohrmann
• Created: 22/Jun/20 09:28
• Updated: 23/Jun/20 06:16
• Resolved: 22/Jun/20 21:01

Description

In order to avoid wrong usage of DualKeyLinkedMap I think we should annotate those methods which can return a null value. That way, the IDE can help highlighting were we access values without proper null checks.

Issue Links

• links to: GitHub Pull Request #12738