docstr: Tests that the update_classy_state successfully updates from a
  checkpoint
docstr_tok: ["Tests","that","the","update_classy_state","successfully","updates","from","a","checkpoint"]
code: def test_update_classy_state(self):
      """
      Tests that the update_classy_state successfully updates from a
      checkpoint
      """
      config = get_fast_test_task_config()
      task = build_task(config)
      task_2 = build_task(config)
      task_2.prepare()
      trainer = LocalTrainer()
      trainer.train(task)
      update_classy_state(task_2, task.get_classy_state(deep_copy=True))
      self._compare_states(
          task.get_classy_state(), task_2.get_classy_state()
      )
  
imports: import copy
  import shutil
  import tempfile
  import unittest
  import unittest.mock
  from pathlib import Path
  import classy_vision.generic.util
  import torch
  import torch.nn
  from classy_vision.generic.util import CHECKPOINT_FILE, get_torch_version, load_checkpoint, save_checkpoint, split_batchnorm_params, Timer, update_classy_model, update_classy_state
  from classy_vision.models import build_model
  from classy_vision.tasks import build_task
  from classy_vision.trainer import LocalTrainer
  from test.generic.config_utils import get_fast_test_task_config, get_test_model_configs
  from test.generic.utils import compare_model_state, compare_states
label_desc: Use image node_id 3 for calling the TestUpdateStateFunctions obj's underlying member method code with example usage: obj.test_update_classy_state() without return types