override func perform() {
    let sourceViewController = self.sourceViewController as! ViewController
    let destinationViewController = self.destinationViewController as! ImageSlideShowViewController

    let layer = destinationViewController.view.layer
    layer.pop_removeAllAnimations()

    NSLog("Layer frame X: %f", layer.frame.origin.x);
    NSLog("Layer frame width: %f", layer.frame.size.width);

    let xAnim = POPSpringAnimation(propertyNamed: kPOPLayerPositionX)
    let sizeAnim = POPSpringAnimation(propertyNamed: kPOPLayerSize)

    xAnim.fromValue = 320
    xAnim.springBounciness = 16
    xAnim.springSpeed = 10

    // About 20% of it's normal size
    sizeAnim.fromValue = NSValue(CGSize: CGSizeMake(64, 114))

    xAnim.completionBlock = { (_, _) in
        NSLog("Animation has completed.");
        NSLog("Layer frame X: %f", layer.frame.origin.x);
    };

    layer.pop_addAnimation(xAnim, forKey:"position")
    layer.pop_addAnimation(sizeAnim, forKey:"size")

    sourceViewController.navigationController?.pushViewController(destinationViewController, animated:false)