class MysqlIdGenerator:
    def __init__(self, engine):
        self.engine = engine

    async def next(self, table):
        tpl = "REPLACE INTO {} (stub) VALUES ('a');"
        sql = tpl.format(table.name)
        sel = "SELECT LAST_INSERT_ID();"
        async with self.engine.acquire() as conn:
            await conn.execute(sql)
            return await (await conn.execute(sel)).scalar()