The @PLUGIN@ exposes a Rest API endpoint to list the owners associated to each file:
GET /changes/{change-id}/revisions/{revision-id}/owners~getFilesOwners { "AJavaFile.java":[{ "name":"John", "id": 1 }, { "name":"Bob", "id": 2 }], "Aptyhonfileroot.py":[{ "name":"John", "id": 1 }, { "name":"Bob", "id": 2 }, { "name":"John", "id": 3 }] }