func activityIndicatorView() -> UIActivityIndicatorView
    {
        let activityView = UIActivityIndicatorView(style: .large)
        activityView.transform = CGAffineTransform.init(scaleX: 2, y: 2)
        self.view.addSubview(activityView)
        activityView.center = CGPoint(x: TabBarViewController.tabBarViewController.view.frame.size.width / 2,
                                      y:TabBarViewController.tabBarViewController.view.frame.size.height / 2.5)
        return activityView
    }