addEvent method
添加事件
registerObject
事件订阅所在容器的对象(用于区分同一class实例后不同的内存地址)
action
事件发送与接收标识
method
事件执行的方法
Implementation
void addEvent(dynamic registerObject, {String? action, Function? method}) {
super.addObjectEvent(_map, registerObject, action: action, method: method);
}