title: How to load all views in UITabBarController?
body: <p>I have not found relevant and up to date answers in the posts related to this question.</p>
  
  <p>I would like to load all viewcontrollers on launch. Currently it launches as expected but when I tap on a bar item (the first time) there is a slight delay to load it because it has not been loaded yet.</p>
  
  <p>How can I do that is Swift ?</p>
  
  <p>Thanks.</p>