code: def sample_notebook_v3_json(sample_notebook_v3):
      return nbformat_writes(sample_notebook_v3)
  
file_path: jupytext/tests/functional/others/test_nbformat_version.py
imports: import pytest
  from nbformat import writes
  from nbformat.v3.nbbase import new_code_cell, new_notebook, new_text_cell, new_worksheet
  from nbformat.v4.nbbase import new_markdown_cell
  from nbformat.v4.nbbase import new_notebook
  from jupytext import reads, writes
  from jupytext.jupytext import NotSupportedNBFormatVersion
label_desc: Use image node_id 2 for calling a global function with example usage: sample_notebook_v3_json(sample_notebook_v3) and returns: nbformat_writes