code: def test_nbconvert_cell(
      script="""# In[2]:
  print('Hello')
  """,
  ):
      nb = jupytext.reads(script, "py")
      script2 = jupytext.writes(nb, "py:percent")
      expected = """# %%
  print('Hello')
  """
      compare(script2, expected)
  
imports: import os
  import pytest
  from nbformat.v4.nbbase import new_code_cell, new_markdown_cell, new_notebook, new_raw_cell
  import jupytext
  from jupytext.compare import compare, compare_notebooks, notebook_model
label_desc: Use image node_id 6 for calling a global function with example usage: test_nbconvert_cell(script) without return types