code: def test_contrastive_search_gpt2(self):
      article = (
          "DeepMind Technologies is a British artificial intelligence subsidiary of Alphabet Inc. and research "
          "laboratory founded in 2010. DeepMind was acquired by Google in 2014. The company is based"
      )
  
      gpt2_tokenizer = GPT2Tokenizer.from_pretrained("gpt2-large")
      gpt2_model = GPT2LMHeadModel.from_pretrained("gpt2-large").to(
          torch_device
      )
      input_ids = gpt2_tokenizer(
          article, return_tensors="pt"
      ).input_ids.to(torch_device)
  
      outputs = gpt2_model.generate(
          input_ids, penalty_alpha=0.6, top_k=4, max_length=256
      )
  
      generated_text = gpt2_tokenizer.batch_decode(
          outputs, skip_special_tokens=True
      )
  
      self.assertListEqual(
          generated_text,
          [
              "DeepMind Technologies is a British artificial intelligence subsidiary of Alphabet Inc. and research "
              "laboratory founded in 2010. DeepMind was acquired by Google in 2014. The company is based in London, "
              "United Kingdom\n\nGoogle has a lot of data on its users and uses it to improve its products, such as "
              "Google Now, which helps users find the information they're looking for on the web. But the company "
              "is not the only one to collect data on its users. Facebook, for example, has its own facial "
              "recognition technology, as well as a database of millions of photos that it uses to personalize its "
              "News Feed.\n\nFacebook's use of data is a hot topic in the tech industry, with privacy advocates "
              "concerned about the company's ability to keep users' information private. In a blog post last "
              'year, Facebook CEO Mark Zuckerberg said his company would "do our best to be transparent about our '
              'data use and how we use it."\n\n"We have made it clear that we do not sell or share your data with '
              'third parties," Zuckerberg wrote. "If you have questions or concerns, please reach out to us at '
              'privacy@facebook.com."\n\nGoogle declined to comment on the privacy implications of its use of data, '
              "but said in a statement to The Associated Press that"
          ],
      )
  
imports: import datetime
  import gc
  import math
  import unittest
  from transformers import GPT2Config, is_torch_available
  from transformers.testing_utils import backend_empty_cache, require_torch, slow, torch_device
  from ...generation.test_utils import GenerationTesterMixin
  from ...test_configuration_common import ConfigTester
  from ...test_modeling_common import ModelTesterMixin, floats_tensor, ids_tensor, random_attention_mask
  from ...test_pipeline_mixin import PipelineTesterMixin
label_desc: Use image node_id 9 for calling the GPT2ModelLanguageGenerationTest obj's underlying member method code with example usage: obj.test_contrastive_search_gpt2() without return types