def unregister(self, device, callback):
if not device:<EOL><INDENT>logger.error("<STR_LIT>", device)<EOL>return<EOL><DEDENT>logger.debug("<STR_LIT>".format(device.name))<EOL>self._callbacks[device].remove(callback)<EOL>self._devices[device.vera_device_id].remove(device)<EOL>
Remove a registered a callback.

        device: device that has the subscription
        callback: callback used in original registration