Initializes a newly allocated set and adds to it objects from another given set.
- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
A set containing objects to add to the receiving set. Each object is retained as it is added.
An initialized objects set containing the objects from
set. The returned set might be different than the original receiver.