在/ MAPBOX中添加注释的方位/旋转

Question

func mapView(_ mapView: MGLMapView, imageFor annotation: MGLAnnotation) -> MGLAnnotationImage? {
let annotation = annotation as! CustomMapAnnotation

var annotationImage = mapView.dequeueReusableAnnotationImage(withIdentifier: annotation.id)

if annotationImage == nil {
    var image = UIImage(named: "taxi")!

    if let heading = annotation.heading {
        image = image.imageRotatedByDegrees(degrees: heading)
    }
    image = image.withAlignmentRectInsets(UIEdgeInsets(top: 0, left: 0, bottom: image.size.height/2, right: 0))

    annotationImage = MGLAnnotationImage(image: image, reuseIdentifier: annotation.id)
}

return annotationImage
}

我已经在出租车预订应用程序中添加了MAPBOX，同时在汽车注释中添加了标题，以便根据道路方向旋转图片，但是其中显示了一些错误，请帮我解决。