`wanted_names` never read its `previous` argument — the caller reassigns
`wanted` from the return value — so the parameter goes rather than gaining
an underscore; its one call site and four test calls follow. Sorts the
imports in test_artifacts.py. Both were failing `make lint-backend` at HEAD.
Regenerates the client, which 8c097d9 left behind when it corrected the
revoke_client docstring.