code: def test_inference_no_head(self):
      directory = "nvidia/megatron-gpt2-345m/"
      if "MYDIR" in os.environ:
          directory = os.path.join(os.environ["MYDIR"], directory)
      model = GPT2LMHeadModel.from_pretrained(directory)
      model.to(torch_device)
      model.half()
  
      input_ids = torch.tensor(
          [[101, 7110, 1005, 1056, 2023, 11333, 17413, 1029, 102]],
          device=torch_device,
          dtype=torch.long,
      )
  
      with torch.no_grad():
          output = model(input_ids).logits
  
      expected_shape = torch.Size((1, 9, 50257))
      self.assertEqual(output.shape, expected_shape)
  
      expected_diag = torch.tensor(
          [
              4.9414,
              -0.2920,
              -1.2148,
              -4.0273,
              -0.5161,
              -5.2109,
              -1.2412,
              -1.8301,
              -1.7734,
              -4.7148,
              -0.2317,
              -1.0811,
              -2.1777,
              0.4141,
              -3.7969,
              -4.0586,
              -2.5332,
              -3.3809,
              4.3867,
          ],
          device=torch_device,
          dtype=torch.half,
      )
  
      for i in range(19):
          r, c = 8 * i // 17, 2792 * i  # along the diagonal
          computed, expected = output[0, r, c], expected_diag[i]
          msg = (
              f"row={r} col={c} computed={computed} expected={expected}"
          )
          self.assertAlmostEqual(
              computed, expected, delta=1e-4, msg=msg
          )
  
imports: import os
  import unittest
  from transformers import is_torch_available
  from transformers.testing_utils import require_sentencepiece, require_tokenizers, require_torch, slow, torch_device
label_desc: Use image node_id 1 for calling the MegatronGPT2IntegrationTest obj's underlying member method code with example usage: obj.test_inference_no_head() without return types