Function object_role 

fn object_role(status: Option<u64>) -> ObjectRole

What an Object Status makes of an object here.

The end-of-track status settles where the track ended and is judged against nothing: draft-23 states no rule about where one may be placed. a_track_may_end_where_it_has_already_been.rs asserts that acceptance.

Every other status is a statement about objects rather than one of them.