public static JsonParser getParser(HiveConf conf) {
    if (HiveConf.getVar(conf, HiveConf.ConfVars.HIVE_EXECUTION_ENGINE).equals("tez")) {
      return new TezJsonParser();
    }
    return null;
  }
@param conf
@return the appropriate JsonParser to print a JSONObject into outputStream.
common/src/java/org/apache/hadoop/hive/common/jsonexplain/JsonParserFactory.java