I'm currently creating an extension on `UILabel` to facilitate observing dynamic type. Once a `UIContentSizeCategoryDidChangeNotification` is received, I'd like my selector to set the label's font by using

```
self.font = UIFont.preferredFontForTextStyle(someUIFontTextStyle)

```

where `someUIFontTextStyle` uses the same `UIFontTextStyle` the label currently exhibits. I had hoped such a property would be accessible via something like `self.font.fontDescriptor.textStyle`, but the truth seems a bit more convoluted.

Is there a way to access the `UIFontTextStyle` property associated with a `UILabel`? 

Solution
========

```
self.font.fontDescriptor().objectForKey(UIFontDescriptorTextStyleAttribute) as? String

```