This is adaptation jquery.fix.clone.js for Yii2.
The preferred way to install this extension is through composer.
Run
php composer.phar require kosv/yii2-jquery-fix-clone "~1.0"
Or, you may add
"kosv/yii2-jquery-fix-clone": "~1.0"
to the require section of your composer.json file and execute php composer.phar update.