def async_rollback(self, config):
    transaction = self._end_transaction()
    if transaction is None:
      return None

    if self._api_version == _CLOUD_DATASTORE_V1:
      req = googledatastore.RollbackRequest()
      req.transaction = transaction
      resp = googledatastore.RollbackResponse()
    else:
      req = transaction
      resp = api_base_pb.VoidProto()

    return self._make_rpc_call(config, 'Rollback', req, resp,
                               get_result_hook=self.__rollback_hook,
                               service_name=self._api_version)
Returns record length for `count` floats.
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/datastore/datastore_rpc.py/TransactionalConnection.async_rollback--crossover with--dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.util/src/openmdao/util/stream.py/Stream.reclen_floats