Button Bouncing Animation

class ButtonAnimationViewController: UIViewController {

   let button: UIButton = {
       let button = UIButton()
       button.layer.cornerRadius = 12
       button.backgroundColor = UIColor.init(red: 48/255, green: 155/255, blue: 255/255, alpha: 1)
       button.setTitle("Am I Animating?", for: .normal)
       return button
   }()
   override func viewDidLoad() {
       super.viewDidLoad()
       
       view.addSubview(button)
       button.translatesAutoresizingMaskIntoConstraints = false
       let constraints = [
           button.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -80),
           button.centerXAnchor.constraint(equalTo: view.centerXAnchor),
           button.widthAnchor.constraint(equalToConstant: 200),
           button.heightAnchor.constraint(equalToConstant: 60)
       ]
       NSLayoutConstraint.activate(constraints)
       button.addTarget(self, action: #selector(buttonSelected(_:)), for: .touchUpInside)
   }
   

   @objc fileprivate func buttonSelected(_ sender: UIButton){
       print("select")
       animateView(sender)
   }
   // animating
   fileprivate func animateView(_ viewToAnimate: UIView) {
   	//처음 눌렀을때
       UIView.animate(withDuration: 0.15,
                      delay: 0,
                      usingSpringWithDamping: 0.3,
                      initialSpringVelocity: 0.5,
                      options: .curveEaseIn,
                      animations: {
                       viewToAnimate.transform = CGAffineTransform(scaleX: 0.92, y: 0.92)
                      }) { (_) in
                      //원상복구!
           UIView.animate(withDuration: 0.15,
                          delay: 0,
                          usingSpringWithDamping: 0.5,
                          initialSpringVelocity: 0.5,
                          options: .curveEaseIn,
                          animations: {
                           viewToAnimate.transform = CGAffineTransform(scaleX: 1, y: 1)
                          }, completion: nil)
       }
   }

}