title: Swift - "use of unresolved identifier"
body: <p>I am studying Swift!
  I want create Main interface on xib.
  But have error "use of unresolved identifier".</p>
  
  <p><a href="https://i.stack.imgur.com/SOdLr.png" rel="noreferrer"><img src="https://i.stack.imgur.com/SOdLr.png" alt="enter image description here"></a></p>
  
  <p>Add code from <code>MainViewController</code></p>
  
  <pre><code>import Foundation
  
  public class MainViewController : BaseViewController {
  
      override func viewWillAppear(animated: Bool) {
          super.viewWillAppear(animated)
  
          // TODO: Write your test code here
          // ...
      } }
  </code></pre>
  
  <p>UPD:(Add image)
  <a href="https://i.stack.imgur.com/NHODh.png" rel="noreferrer"><img src="https://i.stack.imgur.com/NHODh.png" alt="enter image description here"></a></p>