doc: ??

def cancel_subscribe(self, access_token, show_id):
        """doc: ??
        """
        url = 'https://openapi.youku.com/v2/users/subscribe/cancel.json'
        params = {
            'client_id': self.client_id,
            'access_token': access_token,
            'show_id': show_id
        }
        r = requests.post(url, data=params)
        check_error(r)
        return r.json()['result'] == 0