It's true, hallucinations in LLM's can be so consistent that I warn the LLM up front about stuff like "do not use NSCacheDefault, it does not exist, and there is no default value" and then keeping my fingers crossed it doesn't find a roundabout way to introduce it anyway.

Can't really remember what is was exactly anymore, something in Apple's Vision libraries that just kept popping up if I didn't explicitly say to not use it.