if (list == null) { list = new Properties(); }
list = super.getPropertyInfo(list);
    public Properties getPropertyInfo(Properties list) {        if (list == null) {            list = new Properties();        }        list.put(UnitProperty, "Units to use for measurements, from Length.name possibilities.");        list.put(ShowCircleProperty, "Flag to set whether the range circle is drawn at the end of the line (true/false).");        list.put(ShowAngleProperty, "Flag to note the azimuth angle of the line in the information line (true/false).");        list.put(RepaintToCleanProperty, "Flag to tell the map to repaint to clean up on a double click (true/false).");        return list;    }