private void resetResultReader() {
    if (resultReader != null) {
      ServiceUtils.cleanup(log, resultReader);
      resultReader = null;
    }
  }
Reads the temporary results for non-Hive (non-Driver) commands to the
resulting List of strings.
@param nLines number of lines read at once. If it is <= 0, then read all lines.
service/src/java/org/apache/hive/service/cli/operation/HiveCommandOperation.java