create_expires_generator has been renamed to
create_token_expires_in_generator. If you haven't created a subclass of
AuthorizationServer, or you haven't overwrote
create_expires_generator, there is nothing to change.
If you need to rewrite the
create_expires_generator method, you need to change it to:
class MyAuthorizationServer(AuthorizationServer): def create_token_expires_in_generator(self, app): ...