code: function (event, ce) {
              var ret = this.simpleNotify(event, ce);    // return false 等价 preventDefault + stopPropagation
              // return false 等价 preventDefault + stopPropagation
              if (ret === false) {
                  event.halt();
              }
              return ret;
          }
docs: current observer's notification.
  @protected
  @param {KISSY.Event.Object} event
  @param {KISSY.Event.Observable} ce