def async_begin_transaction(self, config, app):
    if not isinstance(app, basestring) or not app:
      raise datastore_errors.BadArgumentError(
          'begin_transaction requires an application id argument (%r)' % (app,))

    if self._api_version == _CLOUD_DATASTORE_V1:
      req = googledatastore.BeginTransactionRequest()
      resp = googledatastore.BeginTransactionResponse()
    else:
      req = datastore_pb.BeginTransactionRequest()
      req.set_app(app)
      if (TransactionOptions.xg(config, self.__config)):
        req.set_allow_multiple_eg(True)
      resp = datastore_pb.Transaction()

    return self._make_rpc_call(config, 'BeginTransaction', req, resp,
                               get_result_hook=self.__begin_transaction_hook,
                               service_name=self._api_version)
Plot Covariance data.
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/datastore/datastore_rpc.py/BaseConnection.async_begin_transaction--crossover with--dataset/ETHPy150Open mne-tools/mne-python/mne/cov.py/Covariance.plot