The methods that objects adopt so that they can act as a "restoration class” for view controllers during state restoration.
- iOS 6.0+
- tvOS 9.0+
To use a class that adopts this protocol, you must assign that class to the
restoration property of one of your app’s view controllers. The method in this protocol should be used to create the view controller, if it does not yet exist, or return an existing view controller object, if one does exist.