Draw route between two core location point

DrawRoutesonMapKit.swift

func drawRoutes(sourceLocation:CLLocationCoordinate2D , destinationLocation:CLLocationCoordinate2D)
    {

        let sourcePlacemark = MKPlacemark(coordinate: sourceLocation, addressDictionary: nil)
        let destinationPlacemark = MKPlacemark(coordinate: destinationLocation, addressDictionary: nil)
        
        
        let sourceMapItem = MKMapItem(placemark: sourcePlacemark)
        let destinationMapItem = MKMapItem(placemark: destinationPlacemark)
        
        
        let directionRequest = MKDirectionsRequest()
        directionRequest.source = sourceMapItem
        directionRequest.destination = destinationMapItem
        directionRequest.transportType = .automobile
        
        
        let directions = MKDirections(request: directionRequest)
        
        
        directions.calculate {
            (response, error) -> Void in
            
            guard let response = response else {
                if let error = error {
                    print("Error: \(error)")
                }
                
                return
            }
            
            let route = response.routes[0]
            self.mapView.add((route.polyline), level: MKOverlayLevel.aboveRoads)
            
            let rect = route.polyline.boundingMapRect
            self.mapView.setRegion(MKCoordinateRegionForMapRect(rect), animated: true)
        }
    }