code: def test_empty_markdown_to_text():
      cell = new_markdown_cell(source="")
      text = RMarkdownCellExporter(cell, "python").cell_to_text()
      assert text == [""]
  
file_path: jupytext/tests/functional/others/test_cells.py
imports: import pytest
  from nbformat.v4.nbbase import new_markdown_cell
  from jupytext.cell_reader import LightScriptCellReader, RMarkdownCellReader, paragraph_is_fully_commented, uncomment
  from jupytext.cell_to_text import RMarkdownCellExporter
label_desc: Use image node_id 11 for calling a global function with example usage: test_empty_markdown_to_text() without return types