public RegisterResponse register(RegisterRequest request, CertificateAndKey certificateAndKey)
throws RestClientException {
URI uri = resolve("extensions/register");
HttpClient httpClient = getHttpClient(certificateAndKey);
HttpRequest httpRequest = httpClient.buildRequest(HttpMethod.POST, uri);
addHeaders(httpRequest);
addHeaders(httpRequest, certificateAndKey);
setEntityJson(httpRequest, request);