private function mapVAlign($vAlign)
    {
        switch ($vAlign) {
            case Alignment::VERTICAL_BOTTOM:
                return 'bottom';
            case Alignment::VERTICAL_TOP:
                return 'top';
            case Alignment::VERTICAL_CENTER:
            case Alignment::VERTICAL_JUSTIFY:
                return 'middle';
            default:
                return 'baseline';
        }
    }