Avoid a package reference being represented as a dependency

I have been developing some simplistic packages and in my mind there is something I cannot understand completely. It is all related to the question whether or not I can 'wrap' somehow a package reference so that it does not break my package.

The concrete setup is as follow:

• I have a package that contains only some extension methods making the work with collections easier. Lets call this package Collection extensions
• I have another package (that I am currently working over) that I want to reference the Collection extensions. But I do not want this Collection extensions package to be listed as a dependency on NuGet as this may lead to some issues whenever there is a mismatch (or a conflict) between the different used versions of the Collection extensions.

I have tried to set the Private assets metadata to All for the package reference but then this is what I encountered: Could not load file or assembly '<assembly_name>'.

I would appreciate your help!

P.S.: Maybe what I want to achieve is not possible (or hard to achieve). If you think like that, please let me know how would you manage such dependencies because I am planning to develop more helper packages and would like to know whether this is a correct approach or not. Thank you in advance!