title: Navigation controller in modal view
body: <p>Currently, when a button is tapped, a UIModalPresentationSheet comes up. I'd like to add a navigation bar at the top of this when it slides up. I've tried a lot of things but nothing seems to work. Here's what i'm currently trying and it returns this error.</p>
  
  <pre><code>    AthleteAdd *addAthlete = [self.storyboard instantiateViewControllerWithIdentifier:@"addAthlete"];
      UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:addAthlete];
      //[self.navigationController pushViewController:addAthlete animated:YES];
  
      addAthlete.delegate = self;
      addAthlete.modalPresentationStyle = UIModalPresentationFormSheet;
    //  UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:addAthlete];
      [self presentViewController:navigationController animated:YES completion:nil];
  </code></pre>
  
  <p>But it pushes it up modally, and without the modalpresentationsheet form. How can I make it so the navigation controller is sized correctly?</p>