title: Why do I have warning "Redundant constraint 'Self' : 'AnyObject'"
body: <p>I have updated my Xcode to 12.5. And now I can see next warning:
  &quot;Redundant constraint 'Self' : 'AnyObject'&quot;
  <a href="https://i.stack.imgur.com/2ttD3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2ttD3.png" alt="enter image description here" /></a></p>
  <p>What does cause this warning?
  (RouterType has to be available only for classes.)</p>