private static LongRangeSet bitwiseMask(long from, long to, long mask) {
    if (to - from > mask) return range(0, mask);
    long min = from & mask;
    long max = to & mask;
    assert min != max;
    if (min < max) return range(min, max);
    return new RangeSet(new long[] {0, max, min, mask});
  }
private static LongRangeSet bitwiseMask(long from, long to, long mask)