title: UITextView *font* property is an optional in iOS 9. Is it nil by default?
body: <p>Apparently iOS 9 changed the <code>UITextView.font</code> property to be a Swift optional type.  Does that imply the font property could be be nil on a new UITextView object (meaning it has to be tested for nil)?</p>
  
  <p>If the font property on a newly construct UITextView object <em>is</em> nil, does that imply that UITextView will use default system font, or choose a user designated default font somehow?</p>