code: def objective(trial: Trial) -> float:
      x1 = trial.suggest_float("x1", 0.1, 3)
      x2 = trial.suggest_float("x2", 0.1, 3, log=True)
      x3 = trial.suggest_float("x3", 2, 4, log=True)
      return x1 + x2 * x3
  
file_path: optuna/tests/importance_tests/test_fanova.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 FanovaImportanceEvaluator
  from optuna.samplers import RandomSampler
  from optuna.trial import create_trial
label_desc: Use image node_id 1 for calling a global function with example usage: objective(trial) and returns: unknown