// TODO(crbug.com/948518): This is a band-aid fix for not crashing when undo the last closed
// tab, should remove later.
/**
     * @return Whether filter should notify observers about the SetIndex call.
     */
protected boolean shouldNotifyObserversOnSetIndex() {
        return true;
    }
protected boolean shouldNotifyObserversOnSetIndex() {
return true;
}
protected boolean shouldNotifyObserversOnSetIndex() {
return true;
}
protected boolean shouldNotifyObserversOnSetIndex() {
return true;
}