code: def test_restore_from_latest_empty_dir(self) -> None:
      input_dim = 2
      save_every_n_train_steps = 2
  
      my_unit = DummyTrainUnit(input_dim=input_dim)
      with tempfile.TemporaryDirectory() as temp_dir:
          bcs_cb = BaseCheckpointSaver(
              temp_dir,
              save_every_n_train_steps=save_every_n_train_steps,
          )
  
          with self.assertLogs(level="WARNING") as log:
              restored = bcs_cb.restore_from_latest(temp_dir, my_unit)
              self.assertEqual(
                  log.output,
                  [
                      f"WARNING:torchtnt.framework.callbacks._checkpoint_utils:Input dirpath doesn't contain any subdirectories: {temp_dir}"
                  ],
              )
              self.assertFalse(restored)
  
imports: import io
  import math
  import os
  import shutil
  import tempfile
  import time
  import unittest
  from typing import Iterable, List, Optional
  from unittest.mock import MagicMock, patch
  import torch
  import torch.distributed
  from torchtnt.framework._test_utils import DummyFitUnit, DummyTrainUnit, generate_random_dataloader, get_dummy_fit_state, get_dummy_train_state
  from torchtnt.framework.callbacks.base_checkpointer import BaseCheckpointer
  from torchtnt.framework.callbacks.checkpointer_types import RestoreOptions
  from torchtnt.framework.callbacks.lambda_callback import Lambda
  from torchtnt.framework.state import State
  from torchtnt.framework.train import train
  from torchtnt.framework.unit import AppStateMixin, TTrainData
  from torchtnt.utils.distributed import get_global_rank
  from torchtnt.utils.env import init_from_env
  from torchtnt.utils.test_utils import spawn_multi_process
label_desc: Use image node_id 5 for calling the BaseCheckpointerTest obj's underlying member method code with example usage: obj.test_restore_from_latest_empty_dir() without return types