code: def test_study_trials_dataframe_with_no_trials() -> None:
      study_with_no_trials = create_study()
      trials_df = study_with_no_trials.trials_dataframe()
      assert trials_df.empty
  
file_path: optuna/tests/study_tests/test_dataframe.py
imports: from __future__ import annotations
  import pandas
  import pytest
  from optuna import create_study
  from optuna import create_trial
  from optuna import Trial
  from optuna.testing.storages import STORAGE_MODES
  from optuna.testing.storages import StorageSupplier
  from optuna.trial import TrialState
label_desc: Use image node_id 1 for calling a global function with example usage: test_study_trials_dataframe_with_no_trials() without return types