code: public void setValue (String name, long value)
      {
          Long oldValue = null;
          if (_prefs.get(name, null) != null || _props.getProperty(name) != null) {
              oldValue = Long.valueOf(_prefs.getLong(name, super.getValue(name, 0L)));
          }
  
          _prefs.putLong(name, value);
          _propsup.firePropertyChange(name, oldValue, Long.valueOf(value));
      }
docs: Sets the value of the specified preference, overriding the value defined in the
  configuration files shipped with the application.