docs: def check_owner_permission(payload, allow_user_owner):
      """Raise ``PermissionDenied``if ``owner`` found in ``data``."""
      for entity_type in ['users', 'groups']:
          for perm_type in ['add', 'remove']:
              for perms in payload.get(entity_type, {}).get(perm_type, {}).values():
                  if 'owner' in perms:
                      if entity_type == 'users' and allow_user_owner:
                          continue
  
                      if entity_type == 'groups':
                          raise exceptions.ParseError("Owner permission cannot be assigned to a group")
  
                      raise exceptions.PermissionDenied("Only owners can grant/revoke owner permission")