def _check_nonce(self, consumer, token, nonce):
        """Verify that the nonce is uniqueish."""
        nonce = self.datastore.lookup_nonce(consumer, token, nonce)
        if nonce:
            raise oauth2.Error(str(nonce) % 'Nonce already used: %s')
dataset/ETHPy150Open benoitc/dj-webmachine/webmachine/auth/oauth.py/OAuthServer._check_nonce/swapped operands of `%`