如何在wagtail模型中拆分菜单？

from wagtail.core.models import Page
from wagtail.core.fields import StreamField
from wagtail.admin.edit_handlers import FieldPanel, StreamFieldPanel
from wagtail.core import blocks

class MenuItem(blocks.StructBlock):
    title = blocks.CharBlock(required=True)
    url = blocks.URLBlock(required=True)

    class Meta:
        icon = 'link'

class MenuBlock(blocks.StructBlock):
    menu_items = blocks.ListBlock(MenuItem())

    class Meta:
        icon = 'list-ul'
        template = 'blocks/menu_block.html'

class HomePage(Page):
    menu = StreamField(MenuBlock())

    content_panels = Page.content_panels + [
        StreamFieldPanel('menu'),
    ]