Swift5+StoryBoardでUIViewを簡単に角丸にする方法

import UIKit

extension UIView {
    
    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }
    
    @IBInspectable
    var borderWidth: CGFloat {
        get {
            return self.layer.borderWidth
        }
        set {
            self.layer.borderWidth = newValue
        }
    }
    
    @IBInspectable
    var borderColor: UIColor? {
        get {
            return UIColor(cgColor: self.layer.borderColor!)
        }
        set {
            self.layer.borderColor = newValue?.cgColor
        }
    }