code: def test_checkpointing(self):
      # make checkpoint directory
      checkpoint_folder = self.base_dir + "/checkpoint/"
      os.mkdir(checkpoint_folder)
  
      config = get_fast_test_task_config()
      cuda_available = torch.cuda.is_available()
      task = build_task(config)
  
      task.prepare()
  
      # create a checkpoint hook
      checkpoint_hook = CheckpointHook(
          checkpoint_folder, {}, phase_types=["train"]
      )
  
      # call the on end phase function
      checkpoint_hook.on_phase_end(task)
  
      # we should be able to train a task using the checkpoint on all available
      # devices
      for use_gpu in {False, cuda_available}:
          # load the checkpoint
          checkpoint = load_checkpoint(checkpoint_folder)
  
          # create a new task
          task = build_task(config)
  
          # set the checkpoint
          task._set_checkpoint_dict(checkpoint)
  
          task.set_use_gpu(use_gpu)
  
          # we should be able to run the trainer using the checkpoint
          trainer = LocalTrainer()
          trainer.train(task)
  
imports: import copy
  import importlib
  import os
  import shutil
  import tempfile
  import torch
  from classy_vision.generic.util import load_checkpoint
  from classy_vision.hooks import CheckpointHook
  from classy_vision.tasks import build_task
  from classy_vision.trainer import LocalTrainer
  from fvcore.common import file_io
  from fvcore.common.file_io import PathHandler, PathManager
  from test.generic.config_utils import get_fast_test_task_config, get_test_task_config
  from test.generic.hook_test_utils import HookTestBase
label_desc: Use image node_id 7 for calling the TestCheckpointHook obj's underlying member method code with example usage: obj.test_checkpointing() without return types