modelManager.addModelElement(e3);
modelManager.addModelElement(e4);
PersistenceManager.getInstance().saveToFile(EWD_FILE);
// restore
modelManager.clearModel();
PersistenceManager.getInstance().loadFromFile(EWD_FILE);
for( ModelElement modelElement : modelManager.getAllModelElements()){
if (modelElement.getClass().equals(TrafficLightModel.class)) {
TrafficLightModel restoredTl1 = (TrafficLightModel) modelElement;
Assert.assertEquals(tl1.getDurations().length, restoredTl1.getDurations().length);