// Textbook fragment 09.02
  static int hashCode(String s) {
    int h=0;
    for (int i=0; i<s.length(); i++) {
      h = (h << 5) | (h >>> 27); // 5-bit cyclic shift of the running sum
      h += (int) s.charAt(i);   // add in next character
    }
    return h;
  }