protected function filterFiles(array $files)
    {
        $filtered = [];
        foreach ($files as $key => $value) {
            if (\is_array($value)) {
                $filtered[$key] = $this->filterFiles($value);
            } elseif ($value instanceof UploadedFile) {
                if ($value->isValid() && $value->getSize() > UploadedFile::getMaxFilesize()) {
                    $filtered[$key] = new UploadedFile(
                        '',
                        $value->getClientOriginalName(),
                        $value->getClientMimeType(),
                        UPLOAD_ERR_INI_SIZE,
                        true
                    );
                } else {
                    $filtered[$key] = new UploadedFile(
                        $value->getPathname(),
                        $value->getClientOriginalName(),
                        $value->getClientMimeType(),
                        $value->getError(),
                        true
                    );
                }
            }
        }

        return $filtered;
    }