code: private static long finalMix64(long h) {
      h ^= h >>> 33;
      h *= 0xff51afd7ed558ccdL;
      h ^= h >>> 33;
      h *= 0xc4ceb9fe1a85ec53L;
      h ^= h >>> 33;
      return h;
    }
docs: Final self mix of h*.
  
  @param h input to final mix
  @return mix