如何使iOS 13地图同时显示用户位置和另一个注记，即使它们距离很近

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate {
    @IBOutlet weak var mapView: MKMapView!
    
    let locationManager = CLLocationManager()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 请求用户授权获取位置信息
        locationManager.requestWhenInUseAuthorization()
        
        // 设置地图显示用户位置
        mapView.showsUserLocation = true
        
        // 设置地图代理
        mapView.delegate = self
        
        // 开始获取用户位置
        locationManager.delegate = self
        locationManager.startUpdatingLocation()
        
        // 添加另一个注记
        let annotation = MKPointAnnotation()
        annotation.coordinate = CLLocationCoordinate2D(latitude: 37.33182, longitude: -122.03118)
        annotation.title = "另一个位置"
        mapView.addAnnotation(annotation)
        
        // 设置地图显示区域
        let userLocation = mapView.userLocation.coordinate
        let annotationLocation = annotation.coordinate
        let centerCoordinate = CLLocationCoordinate2D(latitude: (userLocation.latitude + annotationLocation.latitude) / 2, longitude: (userLocation.longitude + annotationLocation.longitude) / 2)
        let span = MKCoordinateSpan(latitudeDelta: abs(userLocation.latitude - annotationLocation.latitude) * 2, longitudeDelta: abs(userLocation.longitude - annotationLocation.longitude) * 2)
        let region = MKCoordinateRegion(center: centerCoordinate, span: span)
        mapView.setRegion(region, animated: true)
    }
    
    // CLLocationManagerDelegate方法，获取用户位置
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        if let location = locations.last {
            // 处理用户位置更新
        }
    }
}

extension ViewController: MKMapViewDelegate {
    // MKMapViewDelegate方法，自定义注记视图
    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        if annotation is MKUserLocation {
            return nil
        }
        
        let annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: "pin")
        annotationView.canShowCallout = true
        return annotationView
    }
}