title: UILabel textColor property marked as nonnull, but comment as nil by default
body: <p>In the Apple class of <code>UILabel</code></p>
  
  <pre><code>open class UILabel : UIView, NSCoding, UIContentSizeCategoryAdjusting {
  
  
      open var text: String? // default is nil
  
      open var font: UIFont! // default is nil (system font 17 plain)
  
      open var textColor: UIColor! // default is nil (text draws black)
  </code></pre>
  
  <p>but what totaly confuses me, is that <code>font</code> and <code>textColor</code> are marked as ! so they cannot be <code>nil</code> (or else crash), but the comment states </p>
  
  <pre><code>default is nil
  </code></pre>
  
  <p>am i missing smth. or not understand smth. proper, or is this some documentation fault or the var is assigned wrong with ! and should have had ?</p>