code: def test_get_attributes(self):
      x = ModelOutputTest(a=30)
      self.assertEqual(x.a, 30)
      self.assertIsNone(x.b)
      self.assertIsNone(x.c)
      with self.assertRaises(AttributeError):
          _ = x.d
  
file_path: H2O/h2o_flexgen/benchmark/third_party/transformers/tests/utils/test_model_output.py
imports: import unittest
  from dataclasses import dataclass
  from typing import Optional
  from transformers.utils import ModelOutput
label_desc: Use image node_id 1 for calling the ModelOutputTester obj's underlying member method code with example usage: obj.test_get_attributes() without return types