code: function tabBrowser_getTab(index) {
      if (index === undefined)
        index = this.selectedIndex;
  
      return this.getElement({type: "tabs_tab", subtype: "index", value: index});
    }
docs: Get the tab at the specified index
  
  @param {number} index
  Index of the tab
  @returns The requested tab
  @type {ElemBase}