code: def test_ipynb_diff_with_no_change() -> None:
      result = runner.invoke(
          main,
          [
              str(
                  get_case_path(
                      "jupyter", "notebook_without_changes.ipynb"
                  )
              ),
              "--diff",
              f"--config={EMPTY_CONFIG}",
          ],
      )
      expected = "1 file would be left unchanged."
      assert expected in result.output
  
imports: import contextlib
  import pathlib
  import re
  from contextlib import ExitStack
  from dataclasses import replace
  from typing import ContextManager
  import pytest
  from _pytest.monkeypatch import MonkeyPatch
  from click.testing import CliRunner
  from black import Mode, NothingChanged, format_cell, format_file_contents, format_file_in_place, main
  from black.handle_ipynb_magics import jupyter_dependencies_are_installed
  from tests.util import DATA_DIR, get_case_path, read_jupyter_notebook
label_desc: Use image node_id 31 for calling a global function with example usage: test_ipynb_diff_with_no_change() without return types