code: def test_multi_gpu_data_parallel_forward(self):
      # Opt-out of this test.
      pass
  
imports: import copy
  import random
  import unittest
  from transformers import TransfoXLConfig, is_torch_available
  from transformers.testing_utils import require_torch, require_torch_multi_gpu, slow, torch_device
  from ...generation.test_generation_utils import GenerationTesterMixin
  from ...test_configuration_common import ConfigTester
  from ...test_modeling_common import ModelTesterMixin, ids_tensor
label_desc: Use image node_id 8 for calling the TransfoXLModelTest obj's underlying member method code with example usage: obj.test_multi_gpu_data_parallel_forward() without return types