public static function stackedProgressBar(array $bars, $htmlOptions = array())
    {
        if (!empty($bars)) {
            self::addCssClass('progress', $htmlOptions);
            $output = self::openTag('div', $htmlOptions);
            $totalWidth = 0;
            foreach ($bars as $barOptions) {
                if (isset($barOptions['visible']) && !$barOptions['visible']) {
                    continue;
                }
                $width = TbArray::popValue('width', $barOptions, 0);
                $tmp = $totalWidth;
                $totalWidth += $width;
                if ($totalWidth > 100) {
                    $width = 100 - $tmp;
                }
                $output .= self::bar($width, $barOptions);
            }
            $output .= '</div>';
            return $output;
        }
        return '';
    }