code: function (idx) {
          var activeTabElm;
  
          if (this.activeTabId) {
            activeTabElm = this.getEl(this.activeTabId);
            $(activeTabElm).removeClass(this.classPrefix + 'active');
            activeTabElm.setAttribute('aria-selected', "false");
          }
  
          this.activeTabId = 't' + idx;
  
          activeTabElm = this.getEl('t' + idx);
          activeTabElm.setAttribute('aria-selected', "true");
          $(activeTabElm).addClass(this.classPrefix + 'active');
  
          this.items()[idx].show().fire('showtab');
          this.reflow();
  
          this.items().each(function (item, i) {
            if (idx != i) {
              item.hide();
            }
          });
        }
docs: Activates the specified tab by index.
  
  @method activateTab
  @param {Number} idx Index of the tab to activate.