     }
 
     public var alpha: CGFloat {
-        get { return CGColorGetAlpha(self.CGColor) }
-        set { self.colorWithAlphaComponent(newValue) }
+        get { return CGColorGetAlpha(CGColor) }
+        set { colorWithAlphaComponent(newValue) }
     }
 
     public func alpha(value: CGFloat) -> UIColor {
-        return self.colorWithAlphaComponent(value)
+        return colorWithAlphaComponent(value)
     }
 
     // Credit: http://stackoverflow.com/a/31466450

    /// - parameter childController: The view controller to add as a child view controller
    /// - parameter containerView:   A container view where this child view controller will be added. Default is parent view controller's view.
    public func addContainerViewController(childController: UIViewController, containerView: UIView? = nil, enableConstraints: Bool = false, padding: UIEdgeInsets = UIEdgeInsetsZero) {
        guard let containerView = containerView ?? self.view else { return }

        childController.beginAppearanceTransition(true, animated: false)
        childController.willMoveToParentViewController(self)
        self.addChildViewController(childController)
        containerView.addSubview(childController.view)
        childController.view.frame = containerView.bounds
        childController.didMoveToParentViewController(self)


    public func resize(newSize: CGSize, tintColor: UIColor? = nil, completionHandler: (resizedImage: UIImage) -> Void) {
        dispatch_async(dispatch_get_global_queue(QOS_CLASS_USER_INITIATED, 0)) {
            UIGraphicsBeginImageContextWithOptions(newSize, false, 0)
            self.drawInRect(CGRectMake(0, 0, newSize.width, newSize.height))
            let newImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
