NavigationSplitViewにおけるツールバーボタンの削除

import SwiftUI

struct NavigationSplitViewSmp4: View {
    let fruits: [String] = ["apple", "banana", "orenge"]
    let fruitsImg: [String] = ["🍎", "🍌", "🍊"]
    @State private var selected: String?
    @State private var selectedImg: String?
    @State private var columnVisibility =
    NavigationSplitViewVisibility.all
    
    var body: some View {
        NavigationSplitView(columnVisibility: $columnVisibility) {
            List(fruits, id: \.self, selection: $selected) { fruit in
                Text(fruit)
            }
            // サイドバーボタンを削除できる
            .toolbar(removing: .sidebarToggle)
            // 新たにサイドバーボタンを追加
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Close") {
                        columnVisibility = .detailOnly
                    }
                }
            }
        } content: {
            List(fruitsImg, id: \.self, selection: $selectedImg) { fruitImg in
                Text(fruitImg)
            }
        } detail: {
            Text("選択したフルーツ：" + (selected ?? "未選択") + (selectedImg ?? "未選択"))
                // サイドバーを展開するボタン
                .toolbar {
                    ToolbarItem(placement: .navigationBarLeading) {
                        Button("Open") {
                            columnVisibility = .all
                        }
                    }
                }
        }
    }
}