code: def test_mark_cell_with_no_title_and_inner_region(
      script="""# This is a markdown cell
  
  # region {"key": "value"}
  a = 1
  
  # region An inner region
  b = 2
  # endregion
  
  def f(x):
      return x + 1
  
  
  # endregion
  
  
  d = 4
  """,
  ):
      nb = jupytext.reads(script, "py")
      assert nb.cells[0].cell_type == "markdown"
      assert nb.cells[0].source == "This is a markdown cell"
      assert nb.cells[1].cell_type == "code"
      assert nb.cells[1].source == '# region {"key": "value"}\na = 1'
      assert nb.cells[2].cell_type == "code"
      assert nb.cells[2].metadata["title"] == "An inner region"
      assert nb.cells[2].source == "b = 2"
      assert nb.cells[3].cell_type == "code"
      assert nb.cells[3].source == "def f(x):\n    return x + 1"
      assert nb.cells[4].cell_type == "code"
      assert nb.cells[4].source == "# endregion"
      assert nb.cells[5].cell_type == "code"
      assert nb.cells[5].source == "d = 4"
      assert len(nb.cells) == 6
  
      script2 = jupytext.writes(nb, "py")
      compare(script2, script)
  
imports: import jupytext
  from jupytext.compare import compare
label_desc: Use image node_id 3 for calling a global function with example usage: test_mark_cell_with_no_title_and_inner_region(script) without return types