input: def extract_words(sentence: str) -> List[str]:
      """Extracts and returns a list of non-vowel words from the given sentence.
      >>> extract_words("This machine learning project is challenging.")
      ['machine', 'learning', 'project', 'is', 'challenging']
      """
output:     vowels = "aeiouAEIOU"
      words = sentence.split()
      non_vowel_words = [word for word in words if not any(char in vowels for char in word)]
      return non_vowel_words