code: def toMessage(self):
          
          namespace = self.openid_message.getOpenIDNamespace()
          reply = Message(namespace)
          reply.setArg(OPENID_NS, 'mode', 'error')
          reply.setArg(OPENID_NS, 'error', str(self))
  
          if self.contact is not None:
              reply.setArg(OPENID_NS, 'contact', str(self.contact))
  
          if self.reference is not None:
              reply.setArg(OPENID_NS, 'reference', str(self.reference))
  
          return reply
docs: Generate a Message object for sending to the relying party,
          after encoding.