Returns a Boolean value that indicates whether every object in the receiving set is also present in another given set.
- iOS 2.0+
- macOS 10.0+
- UIKit for Mac 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The set with which to compare the receiving set.
true if every object in the receiving set is also present in
Object equality is tested using isEqual:.