message: Don't share state across sessions.
diff: @@ -223,7 +223,8 @@ class RunConfig(run_config_lib.RunConfig):
  # Merge the cluster_def into the ConfigProto.
  if self._session_config is None: # pylint: disable=access-member-before-definition
  - self._session_config = config_pb2.ConfigProto(allow_soft_placement=True)
  + self._session_config = config_pb2.ConfigProto(
  + allow_soft_placement=True, isolate_session_state=True)
  if self._session_config.HasField('cluster_def'):
  raise ValueError(
  'You cannot provide a ClusterResolver and '
  