Chaos, I'm pretty sure Neo wanted to automate the wait_for(), not have a callback function...

Which, by the way, doesn't work. Nor does it need to, because wait_for() will always return immediately, since Neos DLL method will never ever be registered as still running in the engines Scheduler (no will it ever appear there as anything). No idea why he thought wait_for() is needed there, but it's definitely not.