How to use the blackhole.control.setgid function in blackhole

def test_setgid_invalid_group(_):
    cfile = create_config(("group=testgroup",))
    with pytest.raises(SystemExit) as exc:
        Config(cfile).load()
        setgid()
    assert exc.value.code == 64

def test_setgid():
    cfile = create_config(("group=abc",))
    with mock.patch("grp.getgrnam") as mock_getgrnam, mock.patch(
        "os.setgid"
    ) as mock_setgid:
        Config(cfile).load()
        setgid()
    assert mock_getgrnam.called is True
    assert mock_setgid.called is True

def test_setgid_same_group():
    cfile = create_config(("",))
    with mock.patch("os.setgid"):
        Config(cfile).load()
        assert setgid() is None

def test_setgid_no_perms():
    cfile = create_config(("group=testgroup",))
    with mock.patch(
        "grp.getgrnam", side_effect=PermissionError
    ), pytest.raises(SystemExit) as exc:
        Config(cfile).load()
        setgid()
    assert exc.value.code == 77

error occurs or :py:obj:`os.EX_OK` when the program
                        exits cleanly.
    """
    args = parse_cmd_args(sys.argv[1:])
    configure_logs(args)
    logger = logging.getLogger("blackhole")
    if args.test:
        config_test(args)
    try:
        config = Config(args.config_file).load().test()
        config.args = args
        warn_options(config)
        daemon = Daemon(config.pidfile)
        supervisor = Supervisor()
        pid_permissions()
        setgid()
        setuid()
    except (ConfigException, DaemonException) as err:
        logger.critical(err)
        raise SystemExit(os.EX_USAGE)
    except BlackholeRuntimeException as err:
        logger.critical(err)
        raise SystemExit(os.EX_NOPERM)
    if args.background:
        try:
            daemon.daemonize()
        except DaemonException as err:
            supervisor.close_socks()
            logger.critical(err)
            raise SystemExit(os.EX_NOPERM)
    try:
        supervisor.run()

def setup_child(self):
        """Basic setup for the child process and starting it."""
        setgid()
        setuid()
        asyncio.set_event_loop(None)
        if setproctitle:
            setproctitle.setproctitle("blackhole: worker")
        process = Child(self.up_read, self.down_write, self.socks, self.idx)
        process.start()