https://bugzilla.wikimedia.org/show_bug.cgi?id=58789
--- Comment #3 from Merlijn van Deen valhallasw@arctus.nl --- I think we should adapt the must_be decorator to take a new runtime parameter (e.g. as_group), which would override the group defined by the original function.
(this would adapt kwargs inside must_be.decorator.callee)