human
Solve the following python programming problem given the following code:
def _power_off(node, timeout = None) : 
    'Power OFF this node

    :param node: Ironic node one of :class:`ironic.db.models.Node`
    :param timeout: Time in seconds to wait till power off is compelete
    :raises: InvalidParameterValue if a seamicro parameter is invalid.
    :raises: MissingParameterValue if required seamicro parameters are
        missing.
    :returns: Power state of the given node
    ' 
    if (timeout is None) : 
        timeout = CONF.seamicro.action_timeout 
state = [None] 
    retries = [0] 
    seamicro_info = _parse_driver_info (node) 
    server = _get_server (seamicro_info) 
    def _wait_for_power_off(state, retries) : 
        'Called at an interval until the node is powered off.' 
        state [0] = _get_power_status (node) 
        if (state [0] == states.POWER_OFF) : 
            raise loopingcall.LoopingCallDone () 
if (retries [0] > CONF.seamicro.max_retry) : 
            state [0] = states.ERROR 
            raise loopingcall.LoopingCallDone () 
try : 
            retries [0] += 1 
            server.power_off () 
except seamicro_client_exception.ClientException : 
            LOG.warning (_LW ('Power-off failed for node %s.'), node.uuid) 
timer = loopingcall.FixedIntervalLoopingCall (<MASK>, state, retries) 
    timer.start (interval = timeout).wait () 
    return state [0] 
    
    Given the code above, what is a proper replacement for <MASK>? Choose among: state, timeout, node, timer, seamicro_info, retries, server
assistant
#Here is a proper replacement for <MASK>.
def _wait_for_power_off(