block_set_io_throttle complaints Need exactly one of 'device' and 'id'

All of sudden, after a qemu update, block_set_io_throttle does not work anymore.

Full command to QEMU monitor -- 

(qemu) block_set_io_throttle db 0 0 0 0 0 0
Need exactly one of 'device' and 'id'

The help text still point to the same old syntax, which no longer works.