Hey, can you improve pagination management ? I use this api for manage many users and many groups, but each call consume "+1" api call ... For each call, you iterate until result are null. So last call is unless, it's just for test than you don't have other page.

It's possible to use 2 methods :
1 - Use the header return, gitlab give some paging information on header, and the next page if exist .. So you can check this header value pour stop iteration .
2 - You have variable "item per page", so just count call return entry Vs item per page. If return count are < item per page, you don't need to call the next page

Hope you can take time on it. :)