How to use the huey.utils.load_class function in huey

try:
    backend = config['queue']['backend']
except:
    print configuration_message
    sys.exit(1)

_db = settings.DATABASES
if 'default' in _db and _db['default'].get('NAME'):
    backup_name = _db['default']['NAME'].rsplit('/', 1)[-1]
else:
    backup_name = 'huey'

queue = config.pop('queue')
if isinstance(queue, dict):
    QueueClass = load_class(queue['backend'])
    queue = QueueClass(
        queue.get('name', backup_name),
        **queue.get('connection', {})
    )

result_store = config.pop('result_store', None)

if isinstance(result_store, dict):
    DataStoreClass = load_class(result_store['backend'])
    result_store = DataStoreClass(
        result_store.get('name', backup_name),
        **result_store.get('connection', {})
    )

always_eager = config.pop('always_eager', False)
huey = Huey(queue, result_store, always_eager=always_eager)

options, args = parser.parse_args()

    if options.verbose is None:
        loglevel = logging.INFO
    elif options.verbose:
        loglevel = logging.DEBUG
    else:
        loglevel = logging.ERROR

    if len(args) == 0:
        err('Error:   missing import path to `Huey` instance')
        err('Example: huey_consumer.py app.queue.huey_instance')
        sys.exit(1)

    try:
        huey_instance = load_class(args[0])
    except:
        err('Error importing %s' % args[0])
        sys.exit(2)

    consumer = Consumer(
        huey_instance,
        options.logfile,
        loglevel,
        options.threads,
        options.periodic,
        options.initial_delay,
        options.backoff,
        options.max_delay,
        options.utc)
    consumer.run()

backup_name = _db['default']['NAME'].rsplit('/', 1)[-1]
else:
    backup_name = 'huey'

queue = config.pop('queue')
if isinstance(queue, dict):
    QueueClass = load_class(queue['backend'])
    queue = QueueClass(
        queue.get('name', backup_name),
        **queue.get('connection', {})
    )

result_store = config.pop('result_store', None)

if isinstance(result_store, dict):
    DataStoreClass = load_class(result_store['backend'])
    result_store = DataStoreClass(
        result_store.get('name', backup_name),
        **result_store.get('connection', {})
    )

always_eager = config.pop('always_eager', False)
huey = Huey(queue, result_store, always_eager=always_eager)

def load_huey(path):
    try:
        return load_class(path)
    except:
        cur_dir = os.getcwd()
        if cur_dir not in sys.path:
            sys.path.insert(0, cur_dir)
            return load_huey(path)
        err('Error importing %s' % path)
        raise

def load_huey(path):
    try:
        return load_class(path)
    except:
        cur_dir = os.getcwd()
        if cur_dir not in sys.path:
            sys.path.insert(0, cur_dir)
            return load_huey(path)
        err('Error importing %s' % path)
        raise

def dynamic_import(obj, key, required=False):
    try:
        path = obj[key]
    except KeyError:
        if required:
            config_error('Missing required configuration: "%s"' % key)
        return None
    try:
        return load_class(path + '.Components')
    except ImportError:
        config_error('Unable to import %s: "%s"' % (key, path))