- willChangeValueForKey:
Informs the observed object that the value of a given property is about to change.
- willChange:valuesAtIndexes:forKey:
Informs the observed object that the specified change is about to be executed at given indexes for a specified ordered to-many relationship.
- didChange:valuesAtIndexes:forKey:
Informs the observed object that the specified change has occurred on the indexes for a specified ordered to-many relationship.
- willChangeValueForKey:withSetMutation:usingObjects:
Informs the observed object that the specified change is about to be made to a specified unordered to-many relationship.
- didChangeValueForKey:withSetMutation:usingObjects:
Informs the observed object that the specified change was made to a specified unordered to-many relationship.