input: def extract_non_vowel_words(sentence: str) -> List[str]:
      """Extracts and returns a list of non-vowel words from the given sentence.
      Non-vowel words are defined as words that do not contain any vowels (a, e, i, o, u).
      >>> extract_non_vowel_words("This machine learning project is challenging.")
      ['s']
      """
output:     vowels = "aeiouAEIOU"
      words = sentence.split()
      non_vowel_words = [word for word in words if all(char not in vowels for char in word)]
      return non_vowel_words