title: How to convert CNContact to CNMutableContact?
body: <p>I need to get contact, change it, and store back.</p>
  
  <p><code>CNContactStore().unifiedContacts</code> gives me <code>CNContact</code> instance, but <code>CNSaveRequest().update</code> requires <code>CNMutableContact</code>.</p>
  
  <p>How to convert CNContact to CNMutableContact?</p>