Function stateHandler

test/README.example.proof.ts:684–687

({ get, set }: { get: () => T; set: (x: T) => void })

      });

    const stateHandler = <T>({ get, set }: { get: () => T; set: (x: T) => void }) =>
      defineHandlerFor<State<T>>().with((self) =>
        self.resume("state.get", get).resume("state.set", set),
      );

    let n = 10;
    const handler = stateHandler({ get: () => n, set: (x) => (n = x) });