human
I wrote the below code

    if (isinstance(vm_, six.string_types) and (call == 'action')):
        vm_ = {'name': vm_, 'provider': 'joyent'}
    if (call == 'function'):
        raise SaltCloudSystemExit('The    query_instance    action    must    be    called    with    -a    or    --action.')
    __utils__['cloud.fire_event']('event', 'querying    instance', 'salt/cloud/{0}/querying'.format(vm_['name']), sock_dir=__opts__['sock_dir'], transport=__opts__['transport'])
    def _query_ip_address():
        data = show_instance(vm_['name'], call='action')
        if (not data):
            log.error('There    was    an    error    while    querying    Joyent.    Empty    response')
            return False
        if (isinstance(data, dict) and ('error' in data)):
            log.warning('There    was    an    error    in    the    query    {0}'.format(data.get('error')))
            return False
        log.debug('Returned    query    data:    {0}'.format(data))
        if ('primaryIp' in data[1]):
            if (data[1]['state'] == 'running'):
                return data[1]['primaryIp']
        return None
    try:
        data = salt.utils.cloud.wait_for_ip(_query_ip_address, timeout=config.get_cloud_config_value('wait_for_ip_timeout', vm_, __opts__, default=(10 * 60)), interval=config.get_cloud_config_value('wait_for_ip_interval', vm_, __opts__, default=10), interval_multiplier=config.get_cloud_config_value('wait_for_ip_interval_multiplier', vm_, __opts__, default=1))
    except (SaltCloudExecutionTimeout, SaltCloudExecutionFailure) as exc:
        try:
            pass
        except SaltCloudSystemExit:
            pass
        finally:
            raise SaltCloudSystemExit(str(exc))
    return data

What's a good function header?

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

def query_instance(vm_=None, call=None):