PnP Core Baseclasses

Question

I would like to create basic classes of objects in pnp core. This offers me various possibilities to extend them with my own functions and properties.

The only problem is that the standard objects that Pnp Core uses are all internal and sealed.

Is there a clean and simple way to implement this anyway?

PnP Core offers interfaces of the objects but if I create my own base class I have to implement the complete logic again...