Open v4l2loopback device with O_NONBLOCK

I'm writing a python library called [linuxpy](https://github.com/tiagocoutinho/linuxpy) which supports V4L2. One of the features is being able to open de V4L2 device in non blocking mode (O_NONBLOCK) to be cooperative with python async/await. I tried with several real cameras and everything seems to work properly. But when I test v4l2loopback device it blocks waiting for the first frame if I open the v4l2loopback device with O_NONBLOCK. Does anyone know if v4l2loopback supports O_NONBLOCK?