如何在iOS app + Swift中控制谷歌地图的大小？

import GoogleMaps

class MapViewController: UIViewController {
    var mapView: GMSMapView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let camera = GMSCameraPosition.camera(withLatitude: 37.7749, longitude: -122.4194, zoom: 12.0)
        mapView = GMSMapView.map(withFrame: CGRect.zero, camera: camera)
        view = mapView
    }
}

mapView.frame = CGRect(x: 0, y: 0, width: 200, height: 200)

mapView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(mapView)

NSLayoutConstraint.activate([
    mapView.topAnchor.constraint(equalTo: view.topAnchor),
    mapView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
    mapView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
    mapView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
])

mapView.frame = CGRect(x: 0, y: 0, width: view.bounds.width, height: view.bounds.height)