code: def test_cell_metadata_differ():
      nb1 = new_notebook(
          cells=[
              new_code_cell("1"),
              new_code_cell("2", metadata={"additional": "metadata1"}),
          ]
      )
      nb2 = new_notebook(
          cells=[
              new_code_cell("1"),
              new_code_cell("2", metadata={"additional": "metadata2"}),
          ]
      )
      with pytest.raises(NotebookDifference) as exception_info:
          compare_notebooks(nb2, nb1, raise_on_first_difference=False)
      assert (
          "Cell metadata 'additional' 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 18 for calling a global function with example usage: test_cell_metadata_differ() without return types