Flawed exercise - correct style class is UIBarButtonItemStyle, not UIBarButtonStyle

The exercise description says the style class to use is UIBarButtonStyle...which is wrong.(that class doesn't exist) The correct class to use is UIBarButtonItemStyle.

Lost quite some time on this exercise...How is it possible that this error hasn't been corrected, it's not a new course? How do I alert this as an error to teamtreehouse? And how do I go back and rate this challenge - can't seem to go back to the rating view.

Here is the faulty exercise description:

"Next, add a method to the enum named button that returns an instance of the class UIBarButtonItem configured properly. An example of how to create an instance for this task is shown in the comments below. Use the same initializer.

In the method, using the associated values as titles for the button, return a button with style UIBarButtonStyle.done for the done member of the BarButton enum. Similarly for the edit member, return a UIBarButtonItem instance with the style set to UIBarButtonStyle.plain.

In both cases you can pass nil for target and action. Once you have a method, call it on the value we created in the previous task and assign it to a constant named button."