old_contents: import pytest
  
  from ..utils import guess_kind
  
  
  @pytest.mark.parametrize('input,expected', [
      ['pouet.jpg', 'image'],
      ['pouet.jpeg', 'image'],
      ['pouet.png', 'image'],
      ['pouet.mp4', 'video'],
      ['pouet.avi', 'video'],
      ['pouet.mp3', 'audio'],
      ['pouet.ogg', 'audio'],
      ['pouet.pdf', 'pdf'],
      ['pouet', None],
  ])
  def test_guess_kind(input, expected):
      assert guess_kind(input) == expected
  
new_contents: import pytest
  
  from ..utils import guess_kind
  
  
  @pytest.mark.parametrize('input,expected', [
      ['pouet.jpg', 'image'],
      ['pouet.jpeg', 'image'],
      ['pouet.png', 'image'],
      ['pouet.mp4', 'video'],
      ['pouet.avi', 'video'],
      ['pouet.mp3', 'audio'],
      ['pouet.ogg', 'audio'],
      ['pouet.pdf', 'pdf'],
      ['pouet', None],
      ['pouet.xxx', None],
  ])
  def test_guess_kind(input, expected):
      assert guess_kind(input) == expected
  
subject: Add case of unknown extension when testing guess_kind