// init AboveWindow
 AboveWindow.shared.ballWidth = 60
 AboveWindow.shared.isShowPanExitView = true // pan to show exit view
 AboveWindow.shared.ballImage = UIImage(named: "thiago")
/* optional: set init stay postion (default: right of screen edge, middle of horizon)
        let screenSize = UIScreen.main.bounds
        AboveWindow.shared.stayPoint = CGPoint(x: screenSize.width - AboveWindow.shared.ballWidth - 10, y: 600)
// */
 
 // push a new controller to AboveWindow
 let controller = UIViewController()
 controller.view.backgroundColor = .blue
 AboveWindow.shared.push(root: controller, in: self.navigationController)

 // hide the controller in AboveWindow
 AboveWindow.shared.hide()

 // show the origin controller in AboveWindow
 AboveWindow.shared.show()

 // or destroy the controller in AboveWindow
 AboveWindow.shared.destroy()

 // other properties
 AboveWindow.shared.ballView.addSubview(customView) // add custom view into ball you like
 AboveWindow.shared.nav = currentNav // change nav, push method set this property
 AboveWindow.shared.imageView = customImageView

 if AboveWindow.shared.isHideIntoBall {
     // hide into ball, do something
 }