Will this for loop keep executing after the do once node has triggered? (Scratch Pad)

I have a (completely undocumented) Do Once Fn node that when triggered prints output to the (also completely undocumented…) Map For.

My question here is: Does the Do Once Fn node actually stop the for loop from looping further after it has been triggered? Or does it just return the same value to the for loop on every individual loop?

If you don’t know, do you at least know a way I could find out?