final public function getInheritanceCSSClassNames()
    {
        $php_class_name = get_class($this);
        $css_class_names = array();

        // get the ancestors that are swat classes
        while ($php_class_name !== 'SwatCellRenderer') {
            if (strncmp($php_class_name, 'Swat', 4) === 0) {
                $css_class_name = mb_strtolower(
                    preg_replace('/([A-Z])/u', '-\1', $php_class_name)
                );

                if (mb_substr($css_class_name, 0, 1) === '-') {
                    $css_class_name = mb_substr($css_class_name, 1);
                }

                array_unshift($css_class_names, $css_class_name);
            }
            $php_class_name = get_parent_class($php_class_name);
        }

        return $css_class_names;
    }