@utils.decorator
def transactional_async(func, args, kwds, **options):
  options.setdefault('propagation', datastore_rpc.TransactionOptions.ALLOWED)
  if args or kwds:
    return transaction_async(lambda: func(*args, **kwds), **options)
  return transaction_async(func, **options)
The async version of @ndb.transaction.
dataset/ETHPy150Open GoogleCloudPlatform/datastore-ndb-python/ndb/model.py/transactional_async