String[] propertyNames()
      throws IllegalAccessException, InvocationTargetException {
    Set<String> names = propertyNamesSet(); // make sure we initialize if necessary
    return names.toArray(new String[names.size()]);
  }
The save directory if HOME/.beeline/ on UNIX, and
HOME/beeline/ on Windows.
beeline/src/java/org/apache/hive/beeline/BeeLineOpts.java