code: def get_unrecognized_field_info(self, key, value_default=None,
                                      variant_default=None):
          
          value, variant = self.__unrecognized_fields.get(key, (value_default,
                                                                variant_default))
          return value, variant
docs: Get the value and variant of an unknown field in this message.
  
          Args:
            key: The name or number of the field to retrieve.
            value_default: Value to be returned if the key isn't found.
            variant_default: Value to be returned as variant if the key isn't
              found.
  
          Returns:
            (value, variant), where value and variant are whatever was passed
            to set_unrecognized_field.