code: def test_optimum_config(self):
      from optimum.gptq import GPTQQuantizer
  
      config = GPTQConfig(bits=2)
      optimum_config = GPTQQuantizer.from_dict(config.to_dict_optimum())
      self.assertEqual(optimum_config.bits, config.bits)
      new_config = GPTQConfig.from_dict_optimum(
          optimum_config.to_dict()
      )
      self.assertEqual(optimum_config.bits, new_config.bits)
  
imports: import tempfile
  import unittest
  import pytest
  from transformers import AutoModelForCausalLM, AutoTokenizer, GPTQConfig
  from transformers.testing_utils import is_torch_available, require_accelerate, require_auto_gptq, require_optimum, require_torch_gpu, require_torch_multi_gpu, slow
label_desc: Use image node_id 6 for calling the GPTQConfigTest obj's underlying member method code with example usage: obj.test_optimum_config() without return types