def add_prefix(key, identity='image'):
    return '||'.join([settings.THUMBNAIL_KEY_PREFIX, identity, key])
add  new port to router hook callback
dataset/ETHPy150Open mariocesar/sorl-thumbnail/sorl/thumbnail/kvstores/base.py/add_prefix--crossover with--dataset/ETHPy150Open openstack/dragonflow/dragonflow/controller/df_db_notifier.py/DBNotifyInterface.add_new_router_port