docs: @Override
      public synchronized void serialize(DataTree dt, Map<Long, Long> sessions, File snapShot)
              throws IOException {
          if (!close) {
              OutputStream sessOS = new BufferedOutputStream(new FileOutputStream(snapShot));
              CheckedOutputStream crcOut = new CheckedOutputStream(sessOS, new Adler32());
              //CheckedOutputStream cout = new CheckedOutputStream()
              OutputArchive oa = BinaryOutputArchive.getArchive(crcOut);
              FileHeader header = new FileHeader(SNAP_MAGIC, VERSION, dbId);
              serialize(dt,sessions,oa, header);
              long val = crcOut.getChecksum().getValue();
              oa.writeLong(val, "val");
              oa.writeString("/", "path");
              sessOS.flush();
              crcOut.close();
              sessOS.close();
          }
      }