def METHOD_NAME(self, service, cookie, db_session):
    headers = service.revoke_cookie()
    cookie.get_headers.assert_called_once_with(None, max_age=0)
    assert headers == cookie.get_headers.return_value
    assert service._user is None  # pylint: disable=protected-access
    assert db_session.query(AuthTicket).first() is None