def off(self):
        """Send the Off command to an X10 device."""
        msg = X10Send.unit_code_msg(self.address.x10_housecode,
                                    self.address.x10_unitcode)
        self._send_method(msg)

        msg = X10Send.command_msg(self.address.x10_housecode,
                                  X10_COMMAND_OFF)
        self._send_method(msg, False)
        self._update_subscribers(0x00)
Send the Off command to an X10 device.