Returns the class name with which this archiver encodes instances of a given class.
- iOS 2.0+
- macOS 10.2+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
The class for which to determine the translation mapping.
The class name with which the receiver encodes instances of
nil if the receiver does not have a translation mapping for
cls. The class’s separate translation map is not searched.