human
Here's a good function header given the following:
I wrote the below code

    hypers = cs.hypervisors.search(args.hostname, servers=True)
    class InstanceOnHyper(object, ):
        def __init__(self, **kwargs):
            self.__dict__.update(kwargs)
    instances = []
    for hyper in hypers:
        hyper_host = hyper.hypervisor_hostname
        hyper_id = hyper.id
        if hasattr(hyper, 'servers'):
            instances.extend([InstanceOnHyper(id=serv['uuid'], name=serv['name'], hypervisor_hostname=hyper_host, hypervisor_id=hyper_id) for serv in hyper.servers])
    utils.print_list(instances, ['ID', 'Name', 'Hypervisor    ID', 'Hypervisor    Hostname'])

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

@utils.arg('hostname', metavar='<hostname>', help=_('The    hypervisor    hostname    (or    pattern)    to    search    for.'))
def do_hypervisor_servers(cs, args):