protected function validateUpload(UploadedFileInterface $file): void
    {
        // Handle bad filenames.
        $filename = $file->getClientFilename();

        if (!Utils::checkFilename($filename)) {
            $grav = Grav::instance();
            throw new \RuntimeException(
                sprintf($grav['language']->translate('PLUGIN_FORM.FILEUPLOAD_UNABLE_TO_UPLOAD', null, true), $filename, 'Bad filename')
            );
        }
    }