意外的关键字参数“faceted”

我正在尝试使用Django Haystack和Solr实现搜索,但当尝试在搜索索引上实现分面搜索,然后尝试运行服务器时,会出现此错误:

TypeError: 初始化 ()得到意外的关键字参数“faceted”

以下是搜索索引:

import datetime
from haystack.indexes import *
from haystack import site
from resources.models import Resource

class ResourceIndex(SearchIndex):
    text = CharField(document=True, use_template=True)
    author = CharField(model_attr='submitter', faceted=True)
    pub_date = DateTimeField(model_attr='created')

    def get_queryset(self):
        """Used when the entire index for model is updated."""
        return Resource.objects.filter(last_modified__lte=datetime.datetime.now())

site.register(Resource, ResourceIndex)