Create or update Tags related to a post.

        :param bulk_mode: If True, minimize db operations by bulk creating post objects
        :param api_post: the API data for the post
        :param post_tags: a mapping of Tags keyed by post ID
        :return: None

def process_post_tags(self, bulk_mode, api_post, post_tags):
        """
        Create or update Tags related to a post.

        :param bulk_mode: If True, minimize db operations by bulk creating post objects
        :param api_post: the API data for the post
        :param post_tags: a mapping of Tags keyed by post ID
        :return: None
        """
        post_tags[api_post["ID"]] = []
        for api_tag in six.itervalues(api_post["tags"]):
            tag = self.process_post_tag(bulk_mode, api_tag)
            if tag:
                post_tags[api_post["ID"]].append(tag)