/**
     * Checks whether the skin is valid.
     */
    protected function validSkin(): bool
    {
        $this->skinRatio = (int)($this->width($this->skin) / 128);

        $validWidth = $this->width($this->skin) / $this->skinRatio === 128;
        $validHeight = $this->height($this->skin) / $this->skinRatio === 64;

        return ($validWidth && $validHeight) ? true : false;
    }