 
     public var contentSize : CGSize?
     public var blurEffectStyle: UIBlurEffectStyle = .Dark
+    public var identifier: String?
 
     private var contentView : UIView!
     private var backgroundImage : UIImageView!

        self.removeFromSuperview()
    }

    private func snapshot() -> UIImage? {
        let appDelegate = UIApplication.sharedApplication().delegate
        guard let window = appDelegate?.window else { return nil }

        super.init(coder: aDecoder)

        commonInit(UIView(), contentSize: nil)
    }

    public func show() {
