How to make a widget extend a specific class

[DjamelAbbou]

I currently am using hooks_riverpod and functional_widget packages on my project and i was wondering how can i make a functional widget function extend a specific class, for example suppose the following non-functional flutter code:

class Counter extends StateNotifier<int?> {
  //...more code
}

how would i make a functional widget function extend the statenotifier class or any other class i would like ?

[rrousselGit]

There's no support for extending custom classes at the moment, especially non-widget ones.

I have no plan to support that at the moment