UISegmentedControl change number of segments programmatically

adding and deleting segments in swift4 using code

class ViewController: UIViewController {

  @IBOutlet weak var segment1: UISegmentedControl!

  override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
  }

  @IBAction func insert(_ sender: Any) {  
    segment1.insertSegment(withTitle: "\(segment1.numberOfSegments+1)", at: segment1.numberOfSegments, animated: true)  
  }

  @IBAction func remove(_ sender: Any) {  
    segment1.removeSegment(at: segment1.numberOfSegments-1, animated: true)
  }
}