code: def test_reject_unnamed_nondict_metric(
      self, tmp_path: pathlib.Path
  ) -> None:
      tensorboard_path = tmp_path.joinpath("tensorboard")
  
      (
          trial,
          controller,
      ) = pytorch_utils.create_trial_and_trial_controller(
          trial_class=pytorch_onevar_model.OneVarTrial,
          hparams=self.hparams,
          trial_seed=self.trial_seed,
          max_batches=100,
          min_validation_batches=10,
          min_checkpoint_batches=sys.maxsize,
          tensorboard_path=tensorboard_path,
      )
  
      def reducer_fn(_):
          return 1.0
  
      # Inject an unnamed metric which returns a non-dict (which is not allowed).
      controller.context.wrap_reducer(reducer_fn)
  
      with pytest.raises(
          AssertionError, match="name=None but it did not return a dict"
      ):
          controller.run()
  
imports: import contextlib
  import importlib
  import io
  import os
  import pathlib
  import sys
  import typing
  from unittest import mock
  import numpy
  import pytest
  import torch
  from _pytest import monkeypatch
  from torch.distributed import launcher
  import determined
  from determined import pytorch
  from tests.experiment import pytorch_utils, utils
  from tests.experiment.fixtures import pytorch_onevar_model
label_desc: Use image node_id 16 for calling the TestPyTorchTrial obj's underlying member method code with example usage: obj.test_reject_unnamed_nondict_metric(tmp_path) and returns: int