How to give Rounded corners to Top or Bottom for Views or Buttons

self.view.cornerRadius = 10.0
self.view.clipToBounds = true

import UIKit
import PlaygroundSupport

class RoundedCornersController : UIViewController {
    
    var templateView: UIView!
    
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .black
        
        templateView = UIView()
        view.addSubview(templateView)
        
        templateView.translatesAutoresizingMaskIntoConstraints = false
        templateView.widthAnchor.constraint(equalToConstant: 250).isActive = true
        templateView.heightAnchor.constraint(equalToConstant: 250).isActive = true
        templateView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        templateView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
        
        templateView.backgroundColor = UIColor.yellow
        
        self.view = view
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        templateView.roundCorner( 10)
    }
    
}

extension UIView {
    func roundCorner(_ cornerRadius: Double) {
        self.layer.cornerRadius = CGFloat(cornerRadius)
        self.clipsToBounds = true
    }
    
}

// This will present the controller in the Live View window
PlaygroundPage.current.liveView = RoundedCornersController()

 

self.templateView.layer.maskedCorners  =  [.layerMinXMaxYCorner, .layerMaxXMaxYCorner]