code: def test_should_terminate() -> None:
      study = create_study()
  
      # Add dummy trial because Terminator needs at least one trial.
      trial = study.ask()
      study.tell(trial, 0.0)
  
      # Improvement is greater than error.
      terminator = Terminator(
          improvement_evaluator=_StaticImprovementEvaluator(3),
          error_evaluator=StaticErrorEvaluator(0),
          min_n_trials=1,
      )
      assert not terminator.should_terminate(study)
  
      # Improvement is less than error.
      terminator = Terminator(
          improvement_evaluator=_StaticImprovementEvaluator(-1),
          error_evaluator=StaticErrorEvaluator(0),
          min_n_trials=1,
      )
      assert terminator.should_terminate(study)
  
      # Improvement is less than error. However, the number of trials is less than `min_n_trials`.
      terminator = Terminator(
          improvement_evaluator=_StaticImprovementEvaluator(-1),
          error_evaluator=StaticErrorEvaluator(0),
          min_n_trials=2,
      )
      assert not terminator.should_terminate(study)
  
      # Improvement is equal to error.
      terminator = Terminator(
          improvement_evaluator=_StaticImprovementEvaluator(0),
          error_evaluator=StaticErrorEvaluator(0),
          min_n_trials=1,
      )
      assert not terminator.should_terminate(study)
  
file_path: optuna/tests/terminator_tests/test_terminator.py
imports: from __future__ import annotations
  import pytest
  from optuna.study._study_direction import StudyDirection
  from optuna.study.study import create_study
  from optuna.terminator import BaseImprovementEvaluator
  from optuna.terminator import StaticErrorEvaluator
  from optuna.terminator import Terminator
  from optuna.terminator.improvement.evaluator import BestValueStagnationEvaluator
  from optuna.trial import FrozenTrial
label_desc: Use image node_id 2 for calling a global function with example usage: test_should_terminate() without return types