@Override
  public TStruct readStructBegin() throws TException {
    stackLevel++;
    if (stackLevel == 1) {
      topLevelStructFieldID = 0;
      ascending = (topLevelStructFieldID >= sortOrder.length() || sortOrder
          .charAt(topLevelStructFieldID) != '-');
    } else {
      // is this a null?
      // only read the is-null byte for level > 1 because the top-level struct
      // can never be null.
      if (readIsNull()) {
        return null;
      }
    }
    return tstruct;
  }
The escaped byte sequence for the "\1" byte. This cannot be changed alone
without changing the readString() code.
serde/src/java/org/apache/hadoop/hive/serde2/thrift/TBinarySortableProtocol.java