如何使SwiftUI列表/大纲组懒惰地用于像文件系统这样的大树？

import SwiftUI

struct FileItem: Identifiable {
    let id = UUID()
    let name: String
    var children: [FileItem]?
}

struct ContentView: View {
    let fileSystem: [FileItem] = [
        FileItem(name: "Documents", children: [
            FileItem(name: "Text.txt"),
            FileItem(name: "Image.jpg"),
        ]),
        FileItem(name: "Downloads"),
        FileItem(name: "Music", children: [
            FileItem(name: "Song1.mp3"),
            FileItem(name: "Song2.mp3"),
        ]),
    ]
    
    var body: some View {
        List(fileSystem, children: \.children) { item in
            Text(item.name)
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}