private function filterFiles(array $files)
    {
        $result = [];
        //\React\Http\Io\UploadedFile::class;
        foreach ($files as $fileName => $file) {
            if ($file instanceof UploadedFile && $file->error !== UPLOAD_ERR_NO_FILE) {
                $result[$fileName] = $file;
            }
        }

        return $result;
    }