docs: public static void setPreferredAttributeValueForTrafficDirection(TrafficDirection direction, int index, String value) {
  		final Preferences prefs = Preferences.userNodeForPackage(RoadNetworkConstants.class);
  		if (prefs != null) {
  			final StringBuilder keyName = new StringBuilder();
  			keyName.append("TRAFFIC_DIRECTION_VALUE_"); //$NON-NLS-1$
  			keyName.append(direction.name());
  			keyName.append("_"); //$NON-NLS-1$
  			keyName.append(index);
  			String sysDef;
  			try {
  				sysDef = getSystemDefault(direction, index);
  			} catch (IndexOutOfBoundsException exception) {
  				sysDef = null;
  			}
  			if (value == null || "".equals(value) //$NON-NLS-1$
  					|| (sysDef != null && sysDef.equalsIgnoreCase(value))) {
  				prefs.remove(keyName.toString());
  				return;
  			}
  			prefs.put(keyName.toString(), value);
  		}
  	}