private function clearAllCaches()
    {
        $this->clearCache(self::CACHE_KEY_CSS);
        $this->clearCache(self::CACHE_KEY_SELECTOR);
        $this->clearCache(self::CACHE_KEY_XPATH);
        $this->clearCache(self::CACHE_KEY_CSS_DECLARATIONS_BLOCK);
        $this->clearCache(self::CACHE_KEY_COMBINED_STYLES);
    }