public function getAcceptedEncodings()
    {
        if (null === $this->encodings) {
            if (isset($_SERVER['HTTP_ACCEPT_ENCODING'])) {
                $this->encodings = strtolower(trim($_SERVER['HTTP_ACCEPT_ENCODING']));
            } else {
                $this->encodings = '';
            }
        }

        return $this->encodings;
    }