def METHOD_NAME(self):
    self._fetched_members = True
    try:
        self.members = _get_action('member_list')(
            {'model': model, 'session': model.Session},
            {'id': self.id, 'object_type': 'user'}
        )
    except NotAuthorized:
        self.members = _get_action('member_list')(
            {'model': model, 'session': model.Session},
            {'id': self.id, 'include_users': False}
        )
    self.members_num = len(self.members)