RealmSet is a collection that contains no duplicate elements.
Similarly to RealmLists, a RealmSet can operate in managed and unmanaged modes. In managed mode a RealmSet persists all its contents inside a realm whereas in unmanaged mode it functions like a MutableSet.
Managed RealmSets can only be created by Realm and will automatically update their content whenever the underlying Realm is updated. Managed RealmSets can only be accessed using the getter that points to a RealmSet field of a RealmObject.
Observes changes to the RealmSet. The Flow will emit InitialSet once subscribed, and then UpdatedSet on every change to the set. The flow will continue running indefinitely until canceled or until the parent object is deleted.