Test that task validation for more than one change provides different results. This will ensure that the per-change match cache introduced to avoid duplicate queries is being re-newed for each change.
Pick two changes which have different results for atleast one of the task-applicable queries. For example, we can use a task with status:open as applicability, one of the changes can be open and the other one merged.
For example, 12345 is open and 12346 is merged and atleast one task has status:open as applicability. Below query should return different results for both changes:
ssh -x -p 29418 review.example.com gerrit query --format JSON ‘change:12345 OR change:12346’ --task--all --task--preview 12347,1