@Override
  public void writeBool(boolean b) throws TException {
    bout[0] = (b ? (byte) 2 : (byte) 1);
    writeRawBytes(bout, 0, 1);
  }
Whether the current field is sorted ascendingly. Always equals to
sortOrder.charAt(topLevelStructFieldID) != '-'
serde/src/java/org/apache/hadoop/hive/serde2/thrift/TBinarySortableProtocol.java