Programmatically turn off an individual monitor

Question

Is there an API or way to programmatically turn off an individual, external monitor via Objective-C on a Mac?

I'm looking to write a small menubar application that can control a secondary display (without a physical power button), but still keep the primary monitor in use.

Hunting around the API documentation, I can't seem to find anything, other then reading states. So hoping someone else might have an idea.