yii2分页中使用clone作用

use yii\data\Pagination;

$query = Article::find()->where(['status' => 1]);

$countQuery = clone $query;

$pages = new Pagination(['totalCount' => $countQuery->count()]);

$models = $query->offset($pages->offset)

  ->limit($pages->limit)

  ->all();

return $this->render('index', [

  'models' => $models,

  'pages' => $pages,

]);