code: def test_two_cells_with_explicit_start(
      pynb="""# +
  # Cell one
  1 + 1
  
  1 + 1
  
  # +
  # Cell two
  2 + 2
  
  2 + 2
  """,
  ):
      nb = jupytext.reads(pynb, "py")
      assert len(nb.cells) == 2
      assert nb.cells[0].cell_type == "code"
      assert (
          nb.cells[0].source
          == """# Cell one
  1 + 1
  
  1 + 1"""
      )
      assert nb.cells[1].cell_type == "code"
      assert (
          nb.cells[1].source
          == """# Cell two
  2 + 2
  
  2 + 2"""
      )
      pynb2 = jupytext.writes(nb, "py")
      compare(pynb2, pynb)
  
imports: 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
label_desc: Use image node_id 14 for calling a global function with example usage: test_two_cells_with_explicit_start(pynb) without return types