code: def test_target_is_none_and_study_is_multi_obj(
      plot_edf: Callable[..., Any]
  ) -> None:
      study = create_study(directions=["minimize", "minimize"])
      with pytest.raises(ValueError):
          plot_edf(study)
  
imports: from __future__ import annotations
  from io import BytesIO
  from typing import Any
  from typing import Callable
  import numpy
  import pytest
  import optuna
  from optuna import Study
  from optuna.study import create_study
  from optuna.testing.visualization import prepare_study_with_trials
  from optuna.trial import create_trial
  from optuna.visualization import plot_edf
  from optuna.visualization._edf import _EDFInfo
  from optuna.visualization._edf import _get_edf_info
  from optuna.visualization._edf import NUM_SAMPLES_X_AXIS
  from optuna.visualization._plotly_imports import _imports
  from optuna.visualization.matplotlib import plot_edf
  from optuna.visualization.matplotlib._matplotlib_imports import _imports
label_desc: Use image node_id 3 for calling a global function with example usage: test_target_is_none_and_study_is_multi_obj(plot_edf) without return types