def to_postdata(self):
        return '&'.join((escape(str(k)), escape(str(v))) % '%s=%s' for k, v in self.parameters.iteritems())

    # serialize as a url for a GET request
dataset/ETHPy150Open benadida/helios-server/helios_auth/security/oauth.py/OAuthRequest.to_postdata/swapped operands of `%`