code: def test_open_invalid_md_file_fails(invalid_md_file, tmp_path):
      cm = TextFileContentsManager()
      cm.root_dir = str(invalid_md_file.parent)
  
      with pytest.raises(
          HTTPError, match="invalid_file_896.md is not UTF-8 encoded"
      ):
          cm.get(invalid_md_file.name)
  
file_path: jupytext/tests/functional/others/test_invalid_file.py
imports: from pathlib import Path
  import pytest
  from tornado.web import HTTPError
  from jupytext import TextFileContentsManager, read
  from jupytext.cli import jupytext
label_desc: Use image node_id 4 for calling a global function with example usage: test_open_invalid_md_file_fails(invalid_md_file, tmp_path) without return types