Why, you ask?
I’ve found that you can trick Google into accepting sensors as thermostats to report temperature, for example. You can also trick Google into accepting a sensor as a switch, but when you ask about on/off it simply says it’s off no matter what state it’s in.
Is there any way you could link an on/off state with the open/close state of the sensor in the device handler so that you could ask Google if a sensor was on (i.e. “open”) and have it respond whether the device is on (open) or not (closed)?
This could be helpful for people with disabilities who have a hard time checking doors, or lazy people who want to make sure their back patio door is closed when they go to bed.