docs: def response(self, text, response_type='ephemeral', attachments=None):
          """Return a response with json format
  
          :param text: the text returned to the client
          :param response_type: optional. When `in_channel` is assigned,
                                both the response message and the initial
                                message typed by the user will be shared
                                in the channel.
                                When `ephemeral` is assigned, the response
                                message will be visible only to the user
                                that issued the command.
          :param attachments: optional. A list of additional messages
                              for rich response.
          """
          from flask import jsonify
          if attachments is None:
              attachments = []
  
          data = {
              'response_type': response_type,
              'text': text,
              'attachments': attachments,
          }
          return jsonify(**data)