code: def test_batch_generation(self):
      tokenizer = GPT2Tokenizer.from_pretrained(
          "gpt2", pad_token="</s>", padding_side="left"
      )
      inputs = tokenizer(
          ["Hello this is a long string", "Hey"],
          return_tensors="np",
          padding=True,
          truncation=True,
      )
  
      model = FlaxGPT2LMHeadModel.from_pretrained("gpt2")
      model.do_sample = False
      model.config.pad_token_id = model.config.eos_token_id
  
      jit_generate = jax.jit(model.generate)
  
      output_sequences = jit_generate(
          inputs["input_ids"], attention_mask=inputs["attention_mask"]
      ).sequences
  
      output_string = tokenizer.batch_decode(
          output_sequences, skip_special_tokens=True
      )
  
      expected_string = [
          "Hello this is a long string of words. I'm going to try to explain what I mean.",
          "Hey, I'm not sure if I'm going to be able to do",
      ]
  
      self.assertListEqual(output_string, expected_string)
  
imports: import tempfile
  import unittest
  import numpy
  import transformers
  from transformers import GPT2Config, GPT2Tokenizer, is_flax_available, is_torch_available
  from transformers.testing_utils import is_pt_flax_cross_test, require_flax, slow
  from ...generation.test_generation_flax_utils import FlaxGenerationTesterMixin
  from ...test_modeling_flax_common import FlaxModelTesterMixin, floats_tensor, ids_tensor, random_attention_mask
label_desc: Use image node_id 4 for calling the FlaxGPT2ModelTest obj's underlying member method code with example usage: obj.test_batch_generation() without return types