code: def test_parallel_optimize() -> None:
      study = optuna.create_study(sampler=samplers.BruteForceSampler())
      trial1 = study.ask()
      trial2 = study.ask()
      x1 = trial1.suggest_categorical("x", ["a", "b"])
      x2 = trial2.suggest_categorical("x", ["a", "b"])
      assert {x1, x2} == {"a", "b"}
  
file_path: optuna/tests/samplers_tests/test_brute_force.py
imports: import numpy
  import pytest
  import optuna
  from optuna import samplers
  from optuna.samplers._brute_force import _TreeNode
  from optuna.trial import Trial
label_desc: Use image node_id 11 for calling a global function with example usage: test_parallel_optimize() without return types