func willChangeValue (forKey : String)
Informs the observed object that the value of a given property is about to change.
func didChangeValue (forKey : String)
Informs the observed object that the value of a given property has changed.
func willChange (NSKeyValueChange, valuesAt : IndexSet, forKey : String)
Informs the observed object that the specified change is about to be executed at given indexes for a specified ordered to-many relationship.
func willChangeValue (forKey : String, withSetMutation : NSKeyValueSetMutationKind, using: Set<AnyHashable>)
Informs the observed object that the specified change is about to be made to a specified unordered to-many relationship.
func didChangeValue (forKey : String, withSetMutation : NSKeyValueSetMutationKind, using: Set<AnyHashable>)
Informs the observed object that the specified change was made to a specified unordered to-many relationship.