Phpstorm $this->model_name->method() highlighted

at the start of your controller class put phpdoc like this

PHP Code:

/**
* Class Google
* @property Stock_model $stock_model
* @property Shop_model $shop_model
*/


class Google extends Admin_Controller{
 function __construct()
   {
       parent::__construct();
       $this->load->model('back/stock_model');