             name: .UIApplicationDidBecomeActive,
             object: nil
         )
+
+        let xAxis = UIInterpolatingMotionEffect(keyPath: "center.x", type: .tiltAlongHorizontalAxis)
+        let yAxis = UIInterpolatingMotionEffect(keyPath: "center.y", type: .tiltAlongVerticalAxis)
+        xAxis.minimumRelativeValue = 20
+        xAxis.maximumRelativeValue = -20
+        yAxis.minimumRelativeValue = 40
+        yAxis.maximumRelativeValue = -40
+        let effect = UIMotionEffectGroup()
+        effect.motionEffects = [xAxis, yAxis]
+        artworkImageView.addMotionEffect(effect)
     }
 
     func setArtwork(of collection: iTunesMusic.Collection, size: CGFloat) {

let appGroupIdentifier = "group.jp.sora0077.itunesmusic"


final class PlayingViewController: UIViewController {

    private let artworkImageView = UIImageView()
    let blurView = UIVisualEffectView(effect: UIBlurEffect(style: .dark))

    private var animator: UIViewPropertyAnimator!


        }
        animator.startAnimation()
        animator.pauseAnimation()
        animator.fractionComplete = 0.94
    }
}

