Web Remote API command to flip Editor into and out of PIE mode?

I have been able to do various things with the http web remote API although more documentation would be welcome. I am able to issue commands that work when the Editor is in and out of PIE mode. What I have not been able to figure out is how to issue a remote command to flip the editor into and out of PIE mode. This would be very useful and is likely possible. How does one do that?