Description

Desired behavior/Acceptance criteria (returned value, expected error, performance expectations, etc.)

• The current behavior is correct (*), but the implementation can be made nicer if and when T320557 is completed.

(*) The current implementation will catch persistent IDs for Composition and Evaluated implementations, if they show up in Z8K4, in executeInternal(), as a Z9. It will catch persistent IDs for Built-in implementations if they show up (in the same place) as Z14K4.Z6K1. This is probably okay for now, but T320557 might allow us to cover more possible cases in a more principled and neater manner.

• 1. Completion checklist
• Check that all unit tests are still passing. (If the new implementation doesn't get 'implementationId' into the metadata map for all the right cases, tests will fail.)
• Before closing this task, review one by one the checklist available here: https://www.mediawiki.org/wiki/Abstract_Wikipedia_team/Definition_of_Done#Back-end_Task/Bug_completion_checklist