code: def notebook_actual():
      metadata = notebook_metadata()
      metadata["language_info"]["version"] = "3.6.8"
      return new_notebook(
          metadata=metadata,
          cells=[
              new_markdown_cell(
                  "First markdown cell", id="markdown-cell-one"
              ),
              new_code_cell("1 + 1", id="code-cell-one"),
              new_markdown_cell(
                  "Modified markdown cell", id="markdown-cell-two"
              ),
          ],
      )
  
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 3 for calling a global function with example usage: notebook_actual() and returns: new_notebook