Sample use for rendererForOverlay

renderer-for-overlay.swift

func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        // This is the final step. This code can be copied and pasted into your project
        // without thinking on it so much. It simply instantiates a MKTileOverlayRenderer
        // for displaying the tile overlay.
        if let tileOverlay = overlay as? MKTileOverlay {
            return MKTileOverlayRenderer(tileOverlay: tileOverlay)
        } else {
            return MKOverlayRenderer(overlay: overlay)
        }
}