Accesses the metadata collector’s delegate object.
- iOS 9.3+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 9.2+
- watchOS 6.0+
The delegate is held using a zeroing-weak reference, so this property will have a value of
nil after a delegate that was previously set has been deallocated.
This property is not key-value observable.