code: private void writeStartSequence(long xaDataRecorderId) throws IOException, InterruptedException {
        ByteArrayOutputStream byteOut = null;
        try {
           byteOut = new ByteArrayOutputStream();
           DataOutputStream dos = new DataOutputStream(byteOut);
           dos.writeLong(xaDataRecorderId);
           dos.flush();
        } finally {
           if (byteOut != null) {
              IOUtils.closeQuietly(byteOut);
           }
        }
        byte[][] startSequence = new byte[1][];
        startSequence[0] = byteOut.toByteArray();
  
        this.dataLogger.write(XALogRecordType.USER.getType(), startSequence);
     }
docs: start sequence writes the ID of the XADataLogger to identify the content
  of the logger
  
  @param dataRecorder
  DataRecorder that uses /operates on the current physical logger