<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def probe(self, ipaddr=None):
 """ Probe given address for bulb. """

        if ipaddr is None:
            # no address so use broadcast
            ipaddr = self._broadcast_addr

        cmd = {"payloadtype": PayloadType.GET,
               "target": ipaddr}

        self._send_command(cmd)