code: private final boolean cons(int i) {
          switch (sb.charAt(i)) {
          case 'a':
          case 'e':
          case 'i':
          case 'o':
          case 'u':
              return false;
          case 'y':
              return (i==0) ? true : !cons(i-1);
          default:
              return true;
          }
      }
docs: cons(i) is true <=> b[i] is a consonant.