def related_tags(self, tags, max=37):
        from fuku.model.post import Post
        if isinstance(tags, basestring):
            tags = self.parse(tags)
        if tags:
            joins, cause, having = self.__make_query(tags)
            in_q = sql.select([TagPost.post_id.label('id')],
                               from_obj=joins). \
                               group_by(TagPost.post_id)
            if cause:  in_q = in_q.where(sql.and_(*cause))
            if having: in_q = in_q.having(having)
            # Do something, this thing is really hard to understand.
            # ...such as document how it actually works.
            q = sql.select([Tag.id, Tag.name,
                            sql.func.count(Tag.name).label('count')],
                           from_obj=in_q.alias('posts'). \
                           join(TagPost.__table__,
                                TagPost.post_id==Post.id)). \
                                where(Tag.id==TagPost.tag_id). \
                                group_by(Tag.name, Tag.id). \
                                limit(max).order_by(sql.desc('count'))
            return meta.Session.execute(q).fetchall()