removeOwner method
Removes name
and its associated PolicySubject from the owner
group.
Returns the PolicySubject associated with name
before it was removed.
Returns null
if name
was no owner
or there is no owner
group.
Implementation
PolicySubject? removeOwner(String name) {
if (!_groups.containsKey(ownerGroupKey)) return null;
final PolicyGroup owner = _groups[ownerGroupKey]!;
return owner.subjects.remove(name);
}