             action:#selector(actionBack(sender:)),
             for:UIControlEvents.touchUpInside)
         
+        let border:UIView = UIView()
+        border.isUserInteractionEnabled = false
+        border.backgroundColor = UIColor(white:1, alpha:0.1)
+        border.translatesAutoresizingMaskIntoConstraints = false
+        border.clipsToBounds = true
+        
+        addSubview(border)
         addSubview(backButton)
         
         let views:[String:UIView] = [
-            "backButton":backButton]
+            "backButton":backButton,
+            "border":border]
         
         let metrics:[String:CGFloat] = [:]
         

            metrics:metrics,
            views:views))
        addConstraints(NSLayoutConstraint.constraints(
            withVisualFormat:"V:|-0-[backButton(64)]",
            options:[],
            metrics:metrics,
            views:views))

        let count = 0
        return count
    }
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        return UICollectionViewCell()
    }
}
