how set the upper corner radius for view in swift code example

Example 1: add top corner radius swift

extension UIView {
   func roundCorners(corners: UIRectCorner, radius: CGFloat) {
        let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        layer.mask = mask
    }
}

Example 2: add corner radius to uiview swift

view.layer.cornerRadius = 25
view.layer.masksToBounds = true