code: def post(self, bot_id, text, attachments=None):
          
          url = utils.urljoin(self.url, 'post')
          payload = dict(bot_id=bot_id, text=text)
  
          if attachments:
              payload['attachments'] = [a.to_json() for a in attachments]
  
          response = self.session.post(url, json=payload)
          return response.ok
docs: Post a new message as a bot to its room.
  
          :param str bot_id: the ID of the bot
          :param str text: the text of the message
          :param attachments: a list of attachments
          :type attachments: :class:`list`
          :return: ``True`` if successful
          :rtype: bool