void shiftLow() throws IOException {
        int LowHi = (int) (Low >>> 32);
        if (LowHi != 0 || Low < 0xFF000000L) {
            position += cacheSize;
            int temp = _cache;
            do {
                Stream.write(temp + LowHi);
                temp = 0xFF;
            }
            while (--cacheSize != 0);
            _cache = (((int) Low) >>> 24);
        }
        cacheSize++;
        Low = (Low & 0xFFFFFF) << 8;
    }