Returns the class description associated with the given four-character Apple event code,
- macOS 10.0+
Overriding behavior is important here. Multiple classes can have the same code if the classes have an uninterrupted linear inheritance from one another. For example, if class B is a subclass of A and class C is a subclass of B, and all three classes have the same four-character Apple event code, then this method returns the class description for class C.