Connection pool with predefined connections about asynch HOT 4 CLOSED

async def use_pool():
    pool = await asynch.create_pool()
    async with pool.acquire() as conn:
        async with conn.cursor() as cursor:
            await cursor.execute("SELECT 1")
            ret = cursor.fetchone()
            assert ret == (1,)
    pool.close()
    await pool.wait_closed()

async with pool.acquire() as conn:
        async with conn.cursor() as cursor:
            await cursor.execute("SELECT 1")
            ret = cursor.fetchone()