private function copy($source, $target)
    {
        $files = $this->listFiles($source, $target);

        foreach ($files as $newPath => $oldPath) {
            if (!file_exists($newPath)) {
                if (is_dir($oldPath)) {
                    mkdir($newPath, 0755, true);
                } else {
                    copy($oldPath, $newPath);
                }
            }
        }
    }