    def _to_string(self):
        enum_name = None
        value = self._get_calculated_value(self.value)
        for enum, enum_value in vars(self.enum_type).items():
            if value == enum_value:
                enum_name = enum
                break
        if enum_name is None:
            return "(%d) UNKNOWN_ENUM" % value
        else:
            return "(%d) %s" % (value, enum_name)