code: def field_types(self):
          
          if self._field_types is None:
              self._field_types = FieldTypeList(self._version, assistant_sid=self._solution['sid'], )
          return self._field_types
docs: Access the field_types
  
          :returns: twilio.rest.autopilot.v1.assistant.field_type.FieldTypeList
          :rtype: twilio.rest.autopilot.v1.assistant.field_type.FieldTypeList