@com.google.common.eventbus.Subscribe @org.axonframework.eventhandling.annotation.EventHandler public void on(final IconUiEvent<?> event) { final Object eventSource = event.getSource(); if(eventSource instanceof ToDoItemV1_1) { ToDoItemV1_1 dto = (ToDoItemV1_1) eventSource; final String underlyingIconName = container.iconNameOf(dto.getToDoItem()); event.setIconName(underlyingIconName); } }