Returns a mutable set proxy that provides read-write access to the unordered to-many relationship specified by a given key.
- iOS 2.0+
- macOS 10.4+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The name of an unordered to-many relationship.
A mutable set that provides read-write access to the unordered to-many relationship specified by
Objects added to the mutable set proxy become related to the receiver, and objects removed from the mutable set become unrelated. The default implementation recognizes the same simple accessor methods and set accessor methods as
value(for, and follows the same direct instance variable access policies, but always returns a mutable collection proxy object instead of the immutable collection that
value(for would return.