code: def test_text_environment_compute_rewards(self):
      env = TextEnvironment(
          self.gpt2_model,
          self.gpt2_tokenizer,
          tools={"DummyTool": DummyTool()},
          reward_fn=lambda x: [
              torch.tensor(i) for i, _ in enumerate(x)
          ],
          prompt="I am a prompt!\n",
      )
  
      histories = [
          TextHistory(
              "<request><DummyTool>test<call>", torch.tensor([1, 2, 3])
          )
          for _ in range(8)
      ]
      histories = env.compute_reward(histories)
  
      for i in range(8):
          self.assertEqual(histories[i].reward, i)
  
imports: import unittest
  from unittest.mock import patch
  import torch
  from transformers import AutoTokenizer
  from trl import AutoModelForCausalLMWithValueHead, TextEnvironment, TextHistory
label_desc: Use image node_id 7 for calling the TextEnvironmentTester obj's underlying member method code with example usage: obj.test_text_environment_compute_rewards() without return types