title: Who calls the private method during unwinding in Xcode?
body: <p>For implementing <strong>unwind segue</strong> we need make control-drag in the storyboard and
  create <strong>private</strong> method in the destination view controller.</p>
  
  <p>I don't understand : if method <strong>is private</strong>, how it works? Because in the implementation file of my view controller this NOT calling.</p>