def __call__(self, *args):
    name = self.validator.__name__
    for config in args:

      if isinstance(config, (type(None), apiproxy_stub_map.UserRPC)):
        pass
      elif not isinstance(config, BaseConfiguration):
        raise datastore_errors.BadArgumentError(
            'invalid config argument (%r)' % (config,))
      elif name in config._values and self is config._options[name]:
        return config._values[name]
    return None
Gets the first non-None value for this option from the given args.
dataset/ETHPy150Open GoogleCloudPlatform/python-compat-runtime/appengine-compat/exported_appengine_sdk/google/appengine/datastore/datastore_rpc.py/ConfigOption.__call__