title: How to set contact as a favorite contact programmatically in Swift?
body: <p>I am developing an application in which I need to fetch all the contacts from device and then set it to favorite contact on button press. I am able to fetch all contacts using <code>[CNContact]</code> in iOS 9 and 10. But don't know how to set it as a favorite contact.</p>
  
  <p>Can we set CNContact as a favorite contact?
  Can we make changes in CNContact?</p>