Returns a Boolean value that indicates whether the set is a superset of the given set.
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 2.0+
- Xcode 8.0+
A set of the same type as the current set.
true if the set is a superset of
Set A is a superset of another set B if every member of B is also a member of A.