Inserts one overlay object below another.
- iOS 4.0+
- macOS 10.9+
- tvOS 9.0+
The overlay object to insert.
An existing object in the
overlaysarray. This object must exist in the array and must not be
This method inserts the overlay into the
MKOverlay level and positions it relative to the specified sibling. When displayed, this leads to the overlay’s contents being displayed beneath that of its sibling. If sibling is not in the same map level, this method appends the overlay to the end of the list of overlays at the indicated level.