code: function(index, silent) {
              var panel = this.panels.eq(index);
  
              if(!silent) {
                  this._trigger('change', null, {'index': index});
              }
              
              //update state
              if(this.options.multiple) {
                  this._addToSelection(index);
              }
              else {
                  this.options.activeIndex = index;
              }
              this._show(panel);
          }
docs: Activates a tab with given index