private void update(int nBytes, long update) {
      // 1 <= nBytes <= 4
      buffer |= (update & 0xFFFFFFFFL) << shift;
      shift += nBytes * 8;
      length += nBytes;

      if (shift >= 32) {
        h1 = mixH1(h1, mixK1((int)buffer));
        buffer >>>= 32;
        shift -= 32;
      }
    }
private void update(int nBytes, long update)