code: def test_markdown_cell_with_backslash_is_encoded_with_raw_string(
      nb=new_notebook(
          cells=[new_markdown_cell(r"A $\LaTeX$ expression")]
      ),
      py=r'''# %% [markdown]
  r"""
  A $\LaTeX$ expression
  """
  ''',
  ):
      nb.metadata["jupytext"] = {
          "cell_markers": '"""',
          "notebook_metadata_filter": "-all",
      }
      py2 = jupytext.writes(nb, "py:percent")
      compare(py2, py)
  
imports: import pytest
  from nbformat.v4.nbbase import new_markdown_cell, new_notebook
  import jupytext
  from jupytext.compare import compare
label_desc: Use image node_id 1 for calling a global function with example usage: test_markdown_cell_with_backslash_is_encoded_with_raw_string(nb, py) without return types