How to use the feedgenerator.rfc3339_date function in feedgenerator

def add_item_elements(self, handler, item):
        #glommed wholesale from feed generator to change *one* little thing... (mdragon)
        handler.addQuickElement(u"title", item['title'])
        if item['link'] is not None:
            handler.addQuickElement(u"link", u"", {u"href": item['link'], u"rel": u"alternate"})
        if item['pubdate'] is not None:
            handler.addQuickElement(u"updated", feedgenerator.rfc3339_date(item['pubdate']).decode('utf-8'))

        # Author information.
        if item['author_name'] is not None:
            handler.startElement(u"author", {})
            handler.addQuickElement(u"name", item['author_name'])
            if item['author_email'] is not None:
                handler.addQuickElement(u"email", item['author_email'])
            if item['author_link'] is not None:
                handler.addQuickElement(u"uri", item['author_link'])
            handler.endElement(u"author")

        # Unique ID.
        if item['unique_id'] is not None:
            unique_id = item['unique_id']
        else:
            unique_id = "urn:uuid:%s" % uuid.uuid4()