The Step 17 of [Spec](https://w3c.github.io/webdriver/#set-window-rect) says as long as one is not null, we should set them. However, following wpt-test expects no change in such situations. https://github.com/web-platform-tests/wpt/blob/25669365de86f0fc38fd0b6a53699abad63adc2c/webdriver/tests/classic/set_window_rect/set.py#L197-L202 Why? As I checked, the original is also never "200".