private function convertFileInformation($file)
    {
        if ($file instanceof FileUpload) {
            return $file;
        }

        $file = $this->fixPhpFilesArray($file);
        if (is_array($file)) {
            $keys = array_keys($file);
            sort($keys);

            if ($keys == ['error', 'name', 'size', 'tmp_name', 'type']) {
                if (UPLOAD_ERR_NO_FILE == $file['error']) {
                    $file = null;
                } else {
                    $file = new FileUpload($file['tmp_name'], $file['name'], $file['size'], $file['type'], $file['error']);
                }
            } else {
                $file = array_map([$this, 'convertFileInformation'], $file);
            }
        }

        return $file;
    }