Model model,
            ModelBuildingRequest request,
            ModelProblemCollector problems,
            ModelBuildingEventCatapult catapult) {
        ModelBuildingListener listener = request.getModelBuildingListener();

        if (listener != null) {
            ModelBuildingEvent event = new DefaultModelBuildingEvent(model, request, problems);

            catapult.fire(listener, event);
        }
    }