public function has($key, $getExpr = false)
    {
        foreach ($this->options as $option) {
            if (is_array($option)) {
                if (! strcasecmp($key, $option['name'])) {
                    return $getExpr ? $option['expr'] : $option['value'];
                }
            } elseif (! strcasecmp($key, $option)) {
                return true;
            }
        }

        return false;
    }