UUIDs as slug with virtual pages

Kirby 3
1

I have used the Content from a spreadsheet recipe. Now with Kirby 3.8.0 I would really like to be able to use the UUID as the slug for the virtual pages. But as this code runs before the pages are created how can I get the ??? to be the UUID. Any ideas?

class ChargeweightsListPage extends Page
{
    public function children()
    {
        $csv = csv($this->root() . "/list.csv", ",");
        $children = array_map(function ($cw) {
            return [
                "slug" =>  ??????,
                "template" => "card",
                "num" => 0,
                "content" => [
                    "title" =>
                        $cw["Title"] ,
                ],
            ];
        }, $csv);

        return Pages::factory($children, $this);
    }
}