Collection duplicates with callable and its return type

[gms8994]

https://laravel.com/docs/11.x/collections#method-duplicates the source for this suggests that it can take a callable, but that the callable should return a boolean value, though that callable is immediately passed to map. It feels wrong for that to return bool, since (at least my understanding) is that the callable would be used to select the items in the collection that make an individual collection record unique. Am I misunderstanding the use-case for a callable being passed to duplicates?

[henzeb]

It would make sense if it were to return anything to return duplicates based on two keys. Have you tried that? because in that case the docblock is wrong.

[gms8994]

Yep, that's what led me down the path - I assumed the docblock was incorrect once I read the code, but wanted to make sure there wasn't something I was unaware of wrt its expected use. I've opened #53499 to fix this.