LukePOLO\LaraCart\LaraCart::update PHP Method

    public function update()
    {
        $this->session->set($this->prefix . '.' . $this->cart->instance, $this->cart);
        if (config('laracart.cross_devices', false) && $this->authManager->check()) {
            $this->authManager->user()->cart_session_id = $this->session->getId();
            $this->authManager->user()->save();
        }
        $this->session->save();
        $this->events->fire('laracart.update', $this->cart);
    }