code: def to_dict(self):
          
          res = self.serialize(private=True)
          res.update(self.extra_args)
          return res
docs: A wrapper for to_dict the makes sure that all the private information
          as well as extra arguments are included. This method should *not* be
          used for exporting information about the key.
  
          :return: A dictionary representation of the JSON Web key