code: def test_matches_pytorch_bf16(self):
      self.test_matches_pytorch(
          rtol=5e-2,
          atol=1e-5,
          micro_batch_steps=1,
          model_dtype=torch.bfloat16,
          optim_dtype=torch.bfloat16,
      )
  
imports: from contextlib import contextmanager
  import io
  from typing import Callable, Optional, Tuple
  import unittest
  import warnings
  import torch
  from torch.testing._internal import common_utils
  from apex.transformer.testing.distributed_test_base import NcclDistributedTestBase
label_desc: Use image node_id 8 for calling the TestDistributedFusedAdam obj's underlying member method code with example usage: obj.test_matches_pytorch_bf16() without return types