human
I wrote the below code

    hass.data[DOMAIN] = BlinkSystem(config)
    discovery.load_platform(hass, 'camera', DOMAIN, {}, config)
    discovery.load_platform(hass, 'sensor', DOMAIN, {}, config)
    discovery.load_platform(hass, 'binary_sensor', DOMAIN, {}, config)
    def snap_picture(call):
        'Take    a    picture.'
        cameras = hass.data[DOMAIN].blink.cameras
        name = call.data.get(ATTR_FRIENDLY_NAME, '')
        if (name in cameras):
            cameras[name].snap_picture()
    def arm_camera(call):
        'Arm    a    camera.'
        cameras = hass.data[DOMAIN].blink.cameras
        name = call.data.get(ATTR_FRIENDLY_NAME, '')
        value = call.data.get(ATTR_ARMED, True)
        if (name in cameras):
            cameras[name].set_motion_detect(value)
    def arm_system(call):
        'Arm    the    system.'
        value = call.data.get(ATTR_ARMED, True)
        hass.data[DOMAIN].blink.arm = value
        hass.data[DOMAIN].blink.refresh()
    hass.services.register(DOMAIN, 'snap_picture', snap_picture, schema=SNAP_PICTURE_SCHEMA)
    hass.services.register(DOMAIN, 'arm_camera', arm_camera, schema=ARM_CAMERA_SCHEMA)
    hass.services.register(DOMAIN, 'arm_system', arm_system, schema=ARM_SYSTEM_SCHEMA)
    return True

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

def setup(hass, config):