如何将任意小部件放入gtk.Menu？

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

def on_button_clicked(widget):
    print("按钮被点击了！")

def create_menu():
    menu = Gtk.Menu()

    # 创建一个菜单项
    menu_item = Gtk.MenuItem(label="菜单项")
    menu.append(menu_item)

    # 创建一个按钮
    button = Gtk.Button(label="按钮")
    button.connect("clicked", on_button_clicked)
    menu_item.add(button)

    menu.show_all()
    return menu

def main():
    window = Gtk.Window()
    window.connect("destroy", Gtk.main_quit)

    button = Gtk.Button(label="右键点击我")
    menu = create_menu()

    def on_button_press(widget, event):
        if event.button == 3:  # 右键点击
            menu.popup(None, None, None, None, event.button, event.time)

    button.connect("button-press-event", on_button_press)

    window.add(button)
    window.show_all()
    Gtk.main()

if __name__ == "__main__":
    main()