Method rename

examples/demo.php:4810–4810

@return static */

(string $name)

    public function label(): string { return 'pen'; }
    /** @return static */
    public function rename(string $name): static { return $this; }
    /** @return static */
    public static function make(string $color = 'black'): static { return new static($color); }
    private function refill(): void {}            // trip wire — must NOT appear on external $pen->