gungamelib's setPreventLevel()

[psycho_wizrd]

I am currently working on an addon for gungame5 and I would like to know how I could use this to prevent a player from leveling based on a flag set in my code.

As a relative question, registerAddon(addonName) would also be required to use prevent a level, correct?
I guess I am more or less asking for the complete usage of setPreventLevel.