public function getStyleSheetsHtml()
    {
        $styleSheets = '';
        if (!isset($this->styles)) {
            return $styleSheets;
        }

        foreach ($this->styles as $s) {
            $styleSheets .= '<link rel="stylesheet" type="text/css" href="' . $s . '"/>' . "\n";
        }

        return $styleSheets;
    }