def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def process_weight(sym, arg, aux):
            for stride in RpnParam.anchor_generate.stride:
                add_anchor_to_arg(
                    sym, arg, aux, RpnParam.anchor_generate.max_side,
                    stride, RpnParam.anchor_generate.scale,
                    RpnParam.anchor_generate.ratio)