如何在Cocoa应用程序中收到系统时间更改的通知？

import Cocoa

class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(_ aNotification: Notification) {
        // 添加观察者以监听系统时间更改通知
        DistributedNotificationCenter.default().addObserver(self,
                                                        selector: #selector(systemClockDidChange),
                                                        name: .NSSystemClockDidChangeNotification,
                                                        object: nil)
    }

    @objc func systemClockDidChange(_ notification: Notification) {
        print("系统时间已更改")
    }
}