有没有办法向wagtail块添加自定义唯一标识符

from wagtail.core import blocks

class CustomBlock(blocks.StructBlock):
    unique_id = blocks.CharBlock(required=True)

    class Meta:
        icon = 'placeholder'
        label = 'Custom Block'

    def get_definition(self):
        definition = super().get_definition()
        definition['fields'].insert(0, ('unique_id', self.unique_id.field.get_definition()))
        return definition

from wagtail.core.models import Page
from wagtail.core.fields import StreamField

class MyPage(Page):
    content = StreamField([
        ('custom_block', CustomBlock()),
    ])