如何在使用Django Elasticsearch时过滤ForeignKey字段的精确匹配

from django_elasticsearch_dsl import Document, fields
from django_elasticsearch_dsl.registries import registry

class MainModelDocument(Document):
    foreign_key_field = fields.ObjectField(properties={
        'id': fields.IntegerField(),
        'name': fields.TextField(),
        # 其他外键字段的定义
    })

    class Index:
        name = 'mainmodel'

    class Django:
        model = MainModel

@registry.register_document
class ForeignKeyModelDocument(Document):
    class Index:
        name = 'foreignkeymodel'

    class Django:
        model = ForeignKeyModel

    foreign_key_field = fields.ObjectField(properties={
        'id': fields.IntegerField(),
        'name': fields.TextField(),
        # 其他外键字段的定义
    })

# 过滤外键字段的精确匹配
search = ForeignKeyModelDocument.search().filter('term', foreign_key_field__name='example_value')