 public extension UIView {
 
     /// Spring animation with completion handler
-    public static func animate(duration: NSTimeInterval = 0.6, damping: CGFloat = 0.7, velocity: CGFloat = 0, options: UIViewAnimationOptions = .AllowUserInteraction, animations: (Void -> Void), completion: ((Bool) -> Void)?) {
+    public static func animate(duration: NSTimeInterval = 0.6, damping: CGFloat = 0.7, velocity: CGFloat = 0, options: UIViewAnimationOptions = .AllowUserInteraction, animations: (() -> Void), completion: ((Bool) -> Void)?) {
         UIView.animateWithDuration(duration, delay: 0, usingSpringWithDamping: damping, initialSpringVelocity: velocity, options: options, animations: {
             animations()
         }, completion: completion)
     }
 
     /// Spring animation
-    public static func animate(duration: NSTimeInterval = 0.6, damping: CGFloat = 0.7, velocity: CGFloat = 0, options: UIViewAnimationOptions = .AllowUserInteraction, animations: (Void -> Void)) {
+    public static func animate(duration: NSTimeInterval = 0.6, damping: CGFloat = 0.7, velocity: CGFloat = 0, options: UIViewAnimationOptions = .AllowUserInteraction, animations: (() -> Void)) {
         UIView.animateWithDuration(duration, delay: 0, usingSpringWithDamping: damping, initialSpringVelocity: velocity, options: options, animations: {
             animations()
         }, completion: nil)
     }
 
     public func roundCorners(corners: UIRectCorner, radius: CGFloat) {
-        let path = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
-        let mask = CAShapeLayer()
-        mask.path = path.CGPath
-        self.layer.mask = mask
-        self.layer.masksToBounds = true
+        let path             = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
+        let mask            = CAShapeLayer()
+        mask.path           = path.CGPath
+        layer.mask          = mask
+        layer.masksToBounds = true
     }
 
     public var viewController: UIViewController? {

    }

    public var alpha: CGFloat {
        get { return CGColorGetAlpha(self.CGColor) }
        set { self.colorWithAlphaComponent(newValue) }
    }

    public func alpha(value: CGFloat) -> UIColor {
        return self.colorWithAlphaComponent(value)
    }

    // Credit: http://stackoverflow.com/a/31466450

    ///
    /// - parameter childController: The view controller to remove from its parent's children controllers
    public func removeContainerViewController(childController: UIViewController) {
        guard childViewControllers.contains(childController) else { return }

        childController.beginAppearanceTransition(false, animated: false)
        childController.willMoveToParentViewController(nil)
