code: def to_dict(self):
          
          obj_dict = super(PlainText, self).to_dict()
          child_dict = {
              'type': self.__class__.__name__,
              'text': self.text
          }
          obj_dict.update(child_dict)
          return obj_dict
docs: Render a MessageElement as python dict
  
          :return: Python dict representation
          :rtype: dict