code: def _test_module_state_dict(cls, config, rank, group):
      ddp_model = cls.get_wrapped_model(
          group, cuda_first=False, config=config
      )
      autocast = ddp_model.mixed_precision
      cls._train_for_several_steps(ddp_model, 2, autocast)
      state_1 = ddp_model.state_dict()
      # You must make a new FSDP instance to use module.load_state_dict
      unwrapped_model = TransformerWithSharedParams(group)
      unwrapped_model.load_state_dict(state_1)
      new_ddp_model = FSDP(unwrapped_model, group, **config).cuda()
      cls._train_for_several_steps(new_ddp_model, 2, autocast)
      try:
          ddp_model.load_state_dict(new_ddp_model.state_dict())
          assert (
              False
          ), "ddp_model.load_state_dict(new_ddp_model.state_dict()) succeeded"
      except Exception:
          pass
  
imports: import functools
  import unittest
  from parameterized import parameterized
  import pytest
  import torch
  from torch import nn
  from fairscale.fair_dev.testing.testing import dist_init, objects_are_equal, skip_if_cuda, teardown, temp_files_ctx
  from fairscale.internal import torch_version
  from fairscale.nn.data_parallel import FullyShardedDataParallel
  from .test_fsdp import CONFIG_OPTIONS, DistributedTest, NestedWrappedModule, TransformerWithSharedParams, rename_test, spawn_and_init
label_desc: Use image node_id 6 for calling the TestSaveLoadStateDict obj's underlying member method code with example usage: obj._test_module_state_dict(cls, config, rank, group) without return types