Remove unused and broken methods

    def render_html(self, tpl=None, html=None, context=None):

        raise NotImplementedError("Not implemented.")

    def start(self):

        self.clean_partial_pipeline()

        if self.backend.uses_redirect():

            return self.redirect(self.backend.auth_url())

        else:

            return self.html(self.backend.auth_html())

    def complete(self, *args, **kwargs):

        return self.backend.auth_complete(*args, **kwargs)

    def continue_pipeline(self, *args, **kwargs):

        return self.backend.continue_pipeline(*args, **kwargs)

class Storage:

    user = UserAuthnzToken