<?php

​

class Subclass extends DateTimeImmutable

{

}

​

class Unrelated {

    public function doThings(): void {

​

        $foo = new Subclass('2023-01-01 12:12:13');

        $foo2 = $foo->modify('+7 days');

        /** @psalm-trace $foo2 */;

        echo $foo2->format('Y-m-d');

    }

    public function format(int $_p): never { exit; }

}