public function createSymmetricEncryptedRequest(
        string $method,
        string $uri,
        string $body,
        SharedEncryptionKey $key,
        array $headers = []
    ): RequestInterface {
        return new Request(
            $method,
            $uri,
            $headers,
            Base64UrlSafe::encode(Simple::encrypt($body, $key))
        );
    }