jQuery源码分析之Callbacks详解

                        //触发回调函数
                        //调用fireWith并指定上下文
                        return this.fireWith(this, arguments);
                    },
                    empty: function () {
                        //清空list即可
                        if (list)//当这个Callbacks废弃掉的时候，Callbacks不应该可以继续使用
                            list = [];
                        return this;
                    },
                    disable: function () {
                        //废弃这个Callbacks对象，后续的回调函数列表不再执行
                        list = undefined;
                        return this;
                    },
                    disabled: function () {//检测这个Callbacks是否已经废掉
                        //转换为boolean返回
                        return !list;
                    },