title: Getting nil value from entity in core data
body: <p>I am following raywenderlich's tutorial for Core Data : <a href="https://www.raywenderlich.com/173972/getting-started-with-core-data-tutorial-2" rel="nofollow noreferrer">Tutorial</a></p>
  
  <p>the issue I am facing is that in this snippet of code : </p>
  
  <pre><code>let entity = NSEntityDescription.entity(forEntityName: "Person", in: managedContext)!
  let person = NSManagedObject(entity: entity,insertInto: managedContext)
  </code></pre>
  
  <p>The entity value is returned <code>nil</code> and app gets crashed . Is there something that I missed because I have tried 3-4 times but still the same issue</p>