code: def test_read_wrong_ext(tmpdir, nb_file="notebook.ext"):
      nb_file = tmpdir.join(nb_file)
      nb_file.write("{}")
      with pytest.raises(JupytextFormatError):
          jupytext.read(str(nb_file))
  
imports: import pytest
  from nbformat.v4.nbbase import new_notebook
  import jupytext
  from jupytext.formats import JupytextFormatError
label_desc: Use image node_id 1 for calling a global function with example usage: test_read_wrong_ext(tmpdir, nb_file) without return types