code: def test_notebook_metadata_differ():
      nb1 = new_notebook(cells=[new_code_cell("1"), new_code_cell("2")])
      nb2 = new_notebook(
          cells=[new_code_cell("1"), new_code_cell("2")],
          metadata={
              "kernelspec": {
                  "language": "python",
                  "name": "python",
                  "display_name": "Python",
              }
          },
      )
      with pytest.raises(NotebookDifference) as exception_info:
          compare_notebooks(nb2, nb1, raise_on_first_difference=False)
      assert "Notebook metadata differ" in exception_info.value.args[0]
  
imports: import pytest
  from nbformat.v4.nbbase import new_code_cell, new_markdown_cell, new_notebook, new_raw_cell
  from jupytext.compare import NotebookDifference, compare, compare_cells, compare_notebooks
  from jupytext.compare import test_round_trip_conversion
label_desc: Use image node_id 19 for calling a global function with example usage: test_notebook_metadata_differ() without return types