如何使用swift在谷歌地图中自定义iconView？

import GoogleMaps

// 在需要显示地图的ViewController中
class MapViewController: UIViewController {
    var mapView: GMSMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建地图视图
        let camera = GMSCameraPosition.camera(withLatitude: 37.7749, longitude: -122.4194, zoom: 12.0)
        mapView = GMSMapView.map(withFrame: view.bounds, camera: camera)
        view.addSubview(mapView)
        
        // 创建自定义图标视图
        let customIconView = UIImageView(image: UIImage(named: "custom_icon"))
        customIconView.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
        
        // 创建标记对象并设置自定义图标视图
        let marker = GMSMarker()
        marker.position = CLLocationCoordinate2D(latitude: 37.7749, longitude: -122.4194)
        marker.title = "Custom Icon"
        marker.iconView = customIconView
        
        // 将标记添加到地图上
        marker.map = mapView
    }
}