Introducing the usage of Laravel subquery statements

class UserController extends Controller{
    public function index()
    {
        $columns = ['id', 'name', 'email', 'created_at'];
        $users = User::addSelect([
            'last_post_title' => Post::select(['title'])
                ->whereColumn('user_id', 'users.id')
                ->where('status', Post::STATUS_NORMAL)
                ->orderByDesc('created_at')
                ->limit(1)
        ])->orderByDesc('id')->paginate(20, $columns);
        return view('user.index', ['users' => $users]);
    }}