def dunderkey(*args):
    return '__'.join(args)
Update the kind map to include this class.
dataset/ETHPy150Open naiquevin/lookupy/lookupy/dunderkey.py/dunderkey--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/datastore-ndb-python/ndb/model.py/Model._update_kind_map