code: def flex_api(self):
          
          if self._flex_api is None:
              from twilio.rest.flex_api import FlexApi
              self._flex_api = FlexApi(self)
          return self._flex_api
docs: Access the FlexApi Twilio Domain
  
          :returns: FlexApi Twilio Domain
          :rtype: twilio.rest.flex_api.FlexApi