ios推送通知的延迟是多少

iOS推送通知的延迟是多少？

swift
import UIKit
import UserNotifications
class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 请求用户授权显示推送通知
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
            if granted {
                print("用户已授权显示推送通知")
            } else {
                print("用户未授权显示推送通知")
            }
        }
    }
    
    @IBAction func sendNotification(_ sender: UIButton) {
        // 创建推送通知内容
        let content = UNMutableNotificationContent()
        content.title = "新消息"
        content.body = "您有一条新的消息"
        
        // 设置推送通知触发器
        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)
        
        // 创建推送通知请求
        let request = UNNotificationRequest(identifier: "notification", content: content, trigger: trigger)
        
        // 发送推送通知
        UNUserNotificationCenter.current().add(request) { (error) in
            if let error = error {
                print("发送推送通知失败：\(error.localizedDescription)")
            } else {
                print("发送推送通知成功")
            }
        }
    }
}