<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 async def fetchall(self):
 """Fetch all, as per MySQLdb. Pretty useless for large queries, as it is buffered. """

        rows = []
        while True:
            row = await self.fetchone()
            if row is None:
                break
            rows.append(row)
        return rows