private void handleChange( final PropertyChangeEvent event )
{
String property = event.getProperty();
if ( Preferences.CONNECTION_MODE.equals( property ) )
{
GraphDbServiceMode newConnectionMode;
newConnectionMode = GraphDbServiceMode.valueOf( (String) event.getNewValue() );
GraphDbServiceManager sm = Activator.getDefault().getGraphDbServiceManager();
cleanTransactionBeforeShutdown();
sm.setGraphServiceMode( newConnectionMode );
// TODO refresh what needs to be refreshed here