code: def test_feat_importance_cartpole(self):
      config = (
          MARWILConfig().environment("CartPole-v1").framework("torch")
      )
      runner = config.build()
      policy = runner.workers.local_worker().get_policy()
      sample_batch = synchronous_parallel_sample(
          worker_set=runner.workers
      )
  
      for repeat in [1, 10]:
          evaluator = FeatureImportance(policy=policy, repeat=repeat)
  
          estimate = evaluator.estimate(sample_batch)
  
          # Check if the estimate is positive.
          assert all(val > 0 for val in estimate.values())
  
file_path: ray/python/ray/rllib/offline/tests/test_feature_importance.py
imports: import unittest
  import ray
  from ray.rllib.algorithms.marwil import MARWILConfig
  from ray.rllib.execution import synchronous_parallel_sample
  from ray.rllib.offline.feature_importance import FeatureImportance
label_desc: Use image node_id 3 for calling the TestFeatureImportance obj's underlying member method code with example usage: obj.test_feat_importance_cartpole() without return types