human
What is a Python program to print 'Enter    JSON-encoded    service    request:' given the following:
I wrote the below code

    assert options.options.method, 'must    specify    a    service    method    (--method)'
    assert options.options.user_id, 'must    specify    a    user    id    (--user_id)'
    if sys.stdin.isatty():
        print 'Enter    JSON-encoded    service    request:'
    request_body = sys.stdin.read()
    request_dict = json.loads(request_body)
    if (not request_dict.has_key('headers')):
        request_dict['headers'] = dict()
    if (not request_dict['headers'].has_key('version')):
        request_dict['headers']['version'] = MAX_SUPPORTED_MESSAGE_VERSION
    client = DBClient.Instance()
    obj_store = ObjectStore.GetInstance(ObjectStore.PHOTO)
    def _OnService(response_dict):
        logging.info(('result:    %s' % util.ToCanonicalJSON(response_dict, indent=2)))
        callback()
    def _OnQueryUser(user):
        context = base.ViewfinderContext(None)
        context.user = user
        context.device_id = (user.webapp_dev_id if (options.options.device_id is None) else options.options.device_id)
        with stack_context.StackContext(context):
            ServiceHandler.InvokeService(client, obj_store, options.options.method, context.user.user_id, context.device_id, request_dict, callback=_OnService)
    User.Query(client, options.options.user_id, None, _OnQueryUser)

What's a good function header?
assistant
#Here is Python program to print 'Enter    JSON-encoded    service    request:'
.

def _RunService(callback):