code: def test_get_terminator_improvement_info_empty(
      specific_create_study: Callable[[], Study], plot_error: bool
  ) -> None:
      study = specific_create_study()
      info = _get_improvement_info(study, plot_error)
      assert info == _ImprovementInfo(
          trial_numbers=[], improvements=[], errors=None
      )
  
imports: from __future__ import annotations
  from io import BytesIO
  from typing import Any
  from typing import Callable
  import pytest
  from optuna.distributions import FloatDistribution
  from optuna.study import create_study
  from optuna.study import Study
  from optuna.terminator import BaseErrorEvaluator
  from optuna.terminator import BaseImprovementEvaluator
  from optuna.terminator import CrossValidationErrorEvaluator
  from optuna.terminator import RegretBoundEvaluator
  from optuna.terminator import report_cross_validation_scores
  from optuna.terminator import StaticErrorEvaluator
  from optuna.testing.objectives import fail_objective
  from optuna.testing.visualization import prepare_study_with_trials
  from optuna.trial import create_trial
  from optuna.trial import TrialState
  from optuna.visualization import plot_terminator_improvement
  from optuna.visualization._terminator_improvement import _get_improvement_info
  from optuna.visualization._terminator_improvement import _get_y_range
  from optuna.visualization._terminator_improvement import _ImprovementInfo
label_desc: Use image node_id 5 for calling a global function with example usage: test_get_terminator_improvement_info_empty(specific_create_study, plot_error) without return types