protected static function export_customfield_data_unknown(\stdClass $record, \stdClass $field, array $subcontext) {
        $context = \context::instance_by_id($record->contextid);

        $record->fieldtype = $field->type;
        $record->fieldshortname = $field->shortname;
        $record->fieldname = format_string($field->name);
        $record->timecreated = \core_privacy\local\request\transform::datetime($record->timecreated);
        $record->timemodified = \core_privacy\local\request\transform::datetime($record->timemodified);
        unset($record->contextid);
        $record->value = format_text($record->value, $record->valueformat, ['context' => $context]);
        writer::with_context($context)->export_data($subcontext, $record);
    }