code: def test_mean_decrease_impurity_importance_evaluator_max_depth() -> (
      None
  ):
      # Assumes that `seed` can be fixed to reproduce identical results.
  
      study = create_study(sampler=RandomSampler(seed=0))
      study.optimize(objective, n_trials=3)
  
      evaluator = MeanDecreaseImpurityImportanceEvaluator(
          max_depth=1, seed=0
      )
      param_importance = evaluator.evaluate(study)
  
      evaluator = MeanDecreaseImpurityImportanceEvaluator(
          max_depth=2, seed=0
      )
      param_importance_different_max_depth = evaluator.evaluate(study)
  
      assert param_importance != param_importance_different_max_depth
  
file_path: optuna/tests/importance_tests/test_mean_decrease_impurity.py
imports: from typing import Tuple
  import pytest
  from optuna import create_study
  from optuna import Trial
  from optuna.distributions import FloatDistribution
  from optuna.importance import MeanDecreaseImpurityImportanceEvaluator
  from optuna.samplers import RandomSampler
  from optuna.trial import create_trial
label_desc: Use image node_id 4 for calling a global function with example usage: test_mean_decrease_impurity_importance_evaluator_max_depth() without return types