code: function _addEvent(type, handler, isOnce) {
              isOnce = !!isOnce;
              if (Utils.isString(type)) {
                  type = type.match(/\S+/g);
              }
              Utils.each(type, function(currentType) {
                  listen.call(this, this.node, currentType, handler, isOnce);
              }, this);
              return this;
          }
docs: 添加事件统一入口