public function theme($themeName = null, array $options = [])
    {
        if (is_array($themeName)) {
            $options = $themeName;
            $themeName = null;
        }

        if ($themeName === null) {
            $default = Configure::read('jQueryUI.defaultTheme');
            $themeName = $default ? $default : 'Jquery.ui-lightness';
        }
        $out = '';
        list($plugin, $theme) = pluginSplit($themeName);
        $plugin = !$plugin ? 'Jquery' : $plugin;
        $out .= (string)$this->_View->Html->css("{$plugin}.ui/{$theme}/theme.css", $options);
        if (Configure::read('debug')) {
            $out .= (string)$this->_View->Html->css("{$plugin}.ui/{$theme}/jquery-ui.css", $options);
        } else {
            $out .= (string)$this->_View->Html->css("{$plugin}.ui/{$theme}/jquery-ui.min.css", $options);
        }

        if (empty($out)) {
            return;
        }

        return $out;
    }