code: function () {
                  var self = this, attrs = self.getAttrs(), attr, m;
                  for (attr in attrs) {
                      m = ON_SET + ucfirst(attr);
                      if (self[m]) {
                          // 自动绑定事件到对应函数
                          self.on('after' + ucfirst(attr) + 'Change', onSetAttrChange);
                      }
                  }
              }
docs: bind attribute change event
  @protected