code: function addDecorative(c) {
              if (c.$isDecorative !== true) {
                  c.$$isDecorative = true;
              }
              this.$getSuper("insert").call(this, this.kids.length, null, c);
          }
docs: Add the specified component as a decorative item of the menu
  @param {zebkit.ui.Panel} c an UI component
  @method addDecorative