code: def _cons(self, word, i):
          
          if word[i] in self.vowels:
              return False
          if word[i] == 'y':
              if i == 0:
                  return True
              else:
                  return (not self._cons(word, i - 1))
          return True
docs: cons(i) is TRUE <=> b[i] is a consonant.