Returns the annotation view associated with the specified annotation object, if any.
- iOS 3.0+
- macOS 10.9+
- Mac Catalyst 13.0+
- tvOS 9.2+
The annotation object whose view you want.
The annotation view or
nil if the view has not yet been created. This method may also return
nil if the annotation is not in the visible map region and therefore does not have an associated annotation view.