title: "The app references non-public selector" when submitting SceneKit App
body: <p>I'm getting this warning message while validating the app for iTunes Connect. I think it says I'm using a private API but I'm pretty sure it isn't private.</p>
  
  <p>Any ideas?</p>
  
  <p><img src="https://i.stack.imgur.com/tgbto.png" alt="Error Message"></p>