              withTopOffset top: CGFloat = 0,
              bottomOffset bottom: CGFloat = 0,
              layout: LayoutMode = .constraints) -> BorderView {
-        let borderView: BorderView
+        var borderView: BorderView
         
         switch layout {
         case .constraints:

     */
    @discardableResult
    func add(left border: BorderViewProperties,
             withTopOffset top: CGFloat = 0, bottomOffset bottom: CGFloat = 0,
             layout: LayoutMode = .constraints) -> BorderView {
        let borderView: BorderView
        
        switch layout {
        case .constraints:

    required public init(coder: NSCoder) {
        fatalError("You shouldn't create a BorderView this way.")
    }
    
     func clipToBoundsBordersIfNeeded(border: BorderViewProperties) {
        if border.roundedCorners {
            self.layer.cornerRadius = CGFloat(border.thickness / 2)
            self.clipsToBounds = true
        }
    }
}

fileprivate extension UIView {
