docstr: Tests whether no env on workers, but env on eval workers works ok.
docstr_tok: ["Tests","whether","no","env","on","workers",",","but","env","on","eval","workers","works","ok","."]
code: def test_no_env_but_eval_workers_do_have_env(self):
      """Tests whether no env on workers, but env on eval workers works ok."""
      script_path = Path(__file__)
      input_file = os.path.join(
          script_path.parent.parent.parent,
          "tests/data/cartpole/small.json",
      )
  
      env = gym.make("CartPole-v1")
  
      offline_rl_config = (
          BCConfig()
          .environment(
              observation_space=env.observation_space,
              action_space=env.action_space,
          )
          .evaluation(
              evaluation_interval=1,
              evaluation_num_workers=1,
              evaluation_config=BCConfig.overrides(
                  env="CartPole-v1",
                  input_="sampler",
                  observation_space=None,  # Test, whether this is inferred.
                  action_space=None,  # Test, whether this is inferred.
              ),
          )
          .offline_data(input_=[input_file])
      )
  
      bc = offline_rl_config.build()
      bc.train()
      bc.stop()
  
imports: import gymnasium
  import numpy
  import os
  from pathlib import Path
  from random import choice
  import time
  import unittest
  import ray
  import ray.rllib.algorithms.dqn
  from ray.rllib.algorithms.bc import BCConfig
  import ray.rllib.algorithms.ppo
  from ray.rllib.examples.env.multi_agent import MultiAgentCartPole
  from ray.rllib.examples.parallel_evaluation_and_training import AssertEvalCallback
  from ray.rllib.utils.metrics.learner_info import LEARNER_INFO
  from ray.rllib.utils.test_utils import check, framework_iterator
label_desc: Use image node_id 9 for calling the TestAlgorithm obj's underlying member method code with example usage: obj.test_no_env_but_eval_workers_do_have_env() without return types