code: def _add_conversation(self, conversation, events=[],
                            event_cont_token=None):
          
          # pylint: disable=dangerous-default-value
          conv_id = conversation.conversation_id.id
          logger.debug('Adding new conversation: {}'.format(conv_id))
          conv = Conversation(self._client, self._user_list, conversation,
                              events, event_cont_token)
          self._conv_dict[conv_id] = conv
          return conv
docs: Add new conversation from hangouts_pb2.Conversation