code: def test_save_config(self):
      with mock_env_with_temp() as d:
          Checkpoint(self.trainer)
          config = load_yaml(os.path.join(d, "config.yaml"))
          self.assertTrue(config == self.config)
          self.assertTrue(config == self.trainer.config)
  
imports: import contextlib
  import os
  import tempfile
  import unittest
  from copy import deepcopy
  from io import StringIO
  from unittest.mock import Mock, patch
  import torch
  from mmf.common.registry import registry
  from mmf.models.base_model import BaseModel
  from mmf.trainers.callbacks.checkpoint import CheckpointCallback
  from mmf.trainers.callbacks.early_stopping import EarlyStoppingCallback
  from mmf.trainers.callbacks.lr_scheduler import LRSchedulerCallback
  from mmf.utils.checkpoint import Checkpoint
  from mmf.utils.configuration import load_yaml
  from mmf.utils.file_io import PathManager
  from omegaconf import OmegaConf
  from tests.test_utils import compare_state_dicts, skip_if_no_cuda
label_desc: Use image node_id 2 for calling the TestUtilsCheckpoint obj's underlying member method code with example usage: obj.test_save_config() without return types