Laravel. I do not understand the logic of the code?

Question

Laravel

I am learning from the lessons "Laravel Framework from Zero to Pro" . In principle, everything is clear, except for one code...
IndexController

class IndexController extends SiteController {
    public function __construct() {
        $menu = new \Corp\Repositories\MenusRepository(new \Corp\Menu);
        parent::__construct($menu);
        $this->bar = 'right';
        $this->template = env('THEME').'.index';
    }
}

MenusRepository

<?php
namespace Corp\Repositories;

use Corp\Menu;

class MenusRepository extends Repository {
  public function __construct(Menu $menu) {
    $this->model = $menu;
  }
}

?>

So...
I don't understand the functionality of this code.

parent::__construct(new \Corp\Repositories\MenusRepository(new \Corp\Menu));

I know it's a parent class constructor call.
Question about Laravel.
$menu = new \Corp\Repositories\MenusRepository(new \Corp\Menu); For what?
The result is:

public function __construct(Menu new \Corp\Repositories\MenusRepository(new \Corp\Menu)) 
{
  $this->model = $menu;
}

Answer 1

What nonsense are you being taught. Better read the doc and watch the laracasts ( https://laracasts.com). No one in the lair does that.
The env function cannot be used in code at all. All environment variables must be transferred to configs and it is desirable to specify default configs.
But in fact, if you do not understand the logic itself, then learn OOP and SOLID

Answer 2

The author of this code does not own php or laravel at the proper level. Better read the original documentation and delete the laracasts. And your question is related to php.
This code calls the constructor of the parent class, while the interface of the inheritor constructor differs from the parent, which violates the principles of SOLID.
php.net/manual/en/language.oop5.decon.php