code: function redirectFocus () {
      ctrl.styleTabItemFocus = ($mdInteraction.getLastInteractionType() === 'keyboard');
      var tabToFocus = getElements().tabs[ctrl.focusIndex];
      if (tabToFocus) {
        tabToFocus.focus();
      }
    }
docs: This is used to forward focus to tab container elements. This method is necessary to avoid
  animation issues when attempting to focus an item that is out of view.