This is probably possible but not using Google Ads API.
The libraries are largely created automatically. I think the sources to create the data classes (for campaigns, groups etc.) are also included in the library source - a long time ago I had to check something in the .NET library source, downloaded these sources and started studying. In there I found documentation how to create or update these data classes. (I didn't check these document, I was checking for some weird bug.)
So I suggest to download a library of your choice from GitHub, and study how these are created. You may also contact the library maintainers for help.
I hope this helps.
If you get results this way, would you give feedback here too?