aspect_A.setModified(true);
aspect_A.addChild(model);
aspect_A.addChild(visualization);
aspect_A.addChild(simulation);
SerializeTreeVisitor visitor = new SerializeTreeVisitor();
runtime.apply(visitor);
String serialized = visitor.getSerializedTree();
System.out.println(serialized);
Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonParser jp = new JsonParser();
JsonElement je = jp.parse(serialized);