title: can not see the view element on the gradient screen
body: <p>Have ViewHelper class with gradient background</p>
  
  <pre><code>class ViewHelper: UIView{
  class func setBackGroundColor(view: UIView){
      let startColor = UIColor(red:0.84, green:0.82, blue:0.80, alpha:1.0)
      let endColor = UIColor(red:0.19, green:0.26, blue:0.32, alpha:1.0)
      let newLayer = CAGradientLayer()
      newLayer.colors = [startColor.cgColor,endColor.cgColor]
      newLayer.frame = view.frame
      view.layer.addSublayer(newLayer)
  }
  </code></pre>
  
  <p>and MainClass where i set it</p>
  
  <pre><code>class ViewController: UIViewController {
  override func viewDidLoad() {
      super.viewDidLoad()
      ViewHelper.setBackGroundColor(view: self.view)
  }
  </code></pre>
  
  <p>when I insert any view element it is not visible,just my gradient screen.
  <a href="https://i.stack.imgur.com/hctdx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hctdx.png" alt="enter image description here"></a></p>