protected function restoreHeaders()
    {
        foreach ($this->savedMessage['headers'] as $name => $savedValue) {
            $headers = $this->getHeaders()->getAll($name);

            foreach ($headers as $key => $value) {
                if (!isset($savedValue[$key])) {
                    $this->getHeaders()->remove($name, $key);
                }
            }
        }
    }