Round Top Corners of a UIButton in Swift

Question

I know I can round all four corners using:

 myBtn.layer.cornerRadius = 8
 myBtn.layer.masksToBounds = true

Since I only want to round two,

Answer 1

rounding is applied to corner's of view/Button .. , but coming to border of button , it is not applying correctly. can I have any solution for that? @

Here is the code that I have used , which is working (border) in iOS11.0 and above and not in below versions(<11.0)

if #available(iOS 11.0, *) {
        self.layer.cornerRadius = radius
        self.layer.maskedCorners = maskedCorners
    } else {
        let shapeLayer = CAShapeLayer()
        shapeLayer.position = self.center
        self.layer.masksToBounds = true
        self.clipsToBounds = true
        let bezirePath = UIBezierPath(roundedRect: self.bounds,
                                      byRoundingCorners: corners,
                                      cornerRadii: CGSize(width: radius, height: radius))
        shapeLayer.bounds = frame
        shapeLayer.path = bezirePath.cgPath

        self.layer.mask = shapeLayer