Sorry for my late reply. To be honest, I have not idea about that. That was not needed in my case. You can pass parameters from your Jenkinsfile to the shared library but not sure about the other way around. Maybe if elaborate your specific need, we find another way to do it without that.
Sorry for my reply as well...
I was trying to do some modifications to an class object in a library function and explicitly returned the same object to use in the pipeline in the later stages and I could do it with defining the appropriate return type(though def works).
Now it works as expected.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.