human
I wrote the below code

    def mysensors_callback(gateway, msg):
        'Run    when    a    message    from    the    gateway    arrives.'
        if (gateway.sensors[msg.node_id].sketch_name is None):
            _LOGGER.debug('No    sketch_name:    node    %s', msg.node_id)
            return
        child = gateway.sensors[msg.node_id].children.get(msg.child_id)
        if (child is None):
            return
        for value_type in child.values:
            key = (msg.node_id, child.id, value_type)
            if ((child.type not in map_sv_types) or (value_type not in map_sv_types[child.type])):
                continue
            if (key in devices):
                if add_devices:
                    devices[key].schedule_update_ha_state(True)
                else:
                    devices[key].update()
                continue
            name = '{}    {}    {}'.format(gateway.sensors[msg.node_id].sketch_name, msg.node_id, child.id)
            if isinstance(entity_class, dict):
                device_class = entity_class[child.type]
            else:
                device_class = entity_class
            devices[key] = device_class(gateway, msg.node_id, child.id, name, value_type)
            if add_devices:
                _LOGGER.info('Adding    new    devices:    %s', [devices[key]])
                add_devices([devices[key]], True)
            else:
                devices[key].update()
    return mysensors_callback

What's a good function header?

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

def pf_callback_factory(map_sv_types, devices, entity_class, add_devices=None):