docs: def verify(self, **kwargs):
          """
          Implementations MUST either return both a Client Configuration Endpoint
          and a Registration Access Token or neither of them.
          :param kwargs:
          :return: True if the message is OK otherwise False
          """
          super(RegistrationResponse, self).verify(**kwargs)
  
          has_reg_uri = "registration_client_uri" in self
          has_reg_at = "registration_access_token" in self
          if has_reg_uri != has_reg_at:
              raise VerificationError((
                  "Only one of registration_client_uri"
                  " and registration_access_token present"), self)
  
          return True