code: static int computeLockId(String s) {
          // This method handles the following fact: Math.abs(Integer.MIN_VALUE) == Integer.MIN_VALUE
          int hashCode = s.hashCode();
          if (hashCode == Integer.MIN_VALUE) {
              hashCode = 13;
          }
          return Math.abs(hashCode) % 1073741823;
      }
docs: returns an int value between 0 and 1073741823 (exclusive)