docs: @Pure
  	public static Integer getPreferredRoadBorderSize(boolean useSystemValue) {
  		final Preferences prefs = Preferences.userNodeForPackage(RoadNetworkLayerConstants.class);
  		if (prefs != null) {
  			final int size = prefs.getInt("ROAD_BORDER_SIZE", -1); //$NON-NLS-1$
  			if (size >= 0) {
  				return size;
  			}
  		}
  		if (useSystemValue) {
  			return DEFAULT_BORDER_SIZE;
  		}
  		return null;
  	}