gistfile1.txt

    /**
     * @param Length $height
     *
     * @return Volume
     */
    public function withHeight(Length $height): self
    {
        $new = clone $this;
        $new->setHeight($height);

        return $new;
    }

    /**
     * @return Length
     */
    public function getHeight(): Length
    {
        return $this->height;
    }

    /**
     * @param Length $depth
     */
    private function setDepth(Length $depth)
    {
        $this->depth = $depth;
        $this->invalidateComputed();
    }

gistfile2.txt

$volume = Volume::create(Lenght::create(10, 'm'), Lenght::create(10, 'm'), Lenght::create(10, 'm'));
$volume = $volume->withHeight(Lenght::create(10, 'm'))