public void putBytes(DataOutputStream dataOut) throws IOException {
      dataOut.write(readBytes, 0, idx);
      idx = 0;
    }
Writes all the bytes, read or skipped, since the last reset to the specified output stream.
Does a mark and reset after the write.
geode-core/src/main/java/org/apache/geode/internal/statistics/ArchiveSplitter.java