human
I wrote the below code

    gateways = config[DOMAIN][CONF_GATEWAYS]
    interface = config[DOMAIN][CONF_INTERFACE]
    discovery_retry = config[DOMAIN][CONF_DISCOVERY_RETRY]
    from PyXiaomiGateway import PyXiaomiGateway
    hass.data[PY_XIAOMI_GATEWAY] = PyXiaomiGateway(hass.add_job, gateways, interface)
    _LOGGER.debug('Expecting    %s    gateways', len(gateways))
    for _ in range(discovery_retry):
        _LOGGER.info('Discovering    Xiaomi    Gateways    (Try    %s)', (_ + 1))
        hass.data[PY_XIAOMI_GATEWAY].discover_gateways()
        if (len(hass.data[PY_XIAOMI_GATEWAY].gateways) >= len(gateways)):
            break
    if (not hass.data[PY_XIAOMI_GATEWAY].gateways):
        _LOGGER.error('No    gateway    discovered')
        return False
    hass.data[PY_XIAOMI_GATEWAY].listen()
    _LOGGER.debug('Listening    for    broadcast')
    for component in ['binary_sensor', 'sensor', 'switch', 'light', 'cover']:
        discovery.load_platform(hass, component, DOMAIN, {}, config)
    def stop_xiaomi(event):
        'Stop    Xiaomi    Socket.'
        _LOGGER.info('Shutting    down    Xiaomi    Hub.')
        hass.data[PY_XIAOMI_GATEWAY].stop_listen()
    hass.bus.listen_once(EVENT_HOMEASSISTANT_STOP, stop_xiaomi)
    def play_ringtone_service(call):
        'Service    to    play    ringtone    through    Gateway.'
        ring_id = call.data.get(ATTR_RINGTONE_ID)
        gw_sid = call.data.get(ATTR_GW_MAC)
        if ((ring_id is None) or (gw_sid is None)):
            _LOGGER.error('Mandatory    parameters    is    not    specified.')
            return
        ring_id = int(ring_id)
        if (ring_id in [9, (14 - 19)]):
            _LOGGER.error('Specified    mid:    %s    is    not    defined    in    gateway.', ring_id)
            return
        ring_vol = call.data.get(ATTR_RINGTONE_VOL)
        if (ring_vol is None):
            ringtone = {'mid': ring_id}
        else:
            ringtone = {'mid': ring_id, 'vol': int(ring_vol)}
        gw_sid = gw_sid.replace(':', '').lower()
        for (_, gateway) in...

What's a good function header?

Here's a good function header?
assistant
#Here's a good function header.

def setup(hass, config):