T call() throws IOException, RegistryException {
    String apiRouteBase = "https://" + registryEndpointRequestProperties.getServerUrl() + "/v2/";
    URL initialRequestUrl = registryEndpointProvider.getApiRoute(apiRouteBase);
    return call(initialRequestUrl);
  }
@Test
  public void testCall_unknown() throws IOException, RegistryException {
    ResponseException responseException =
        mockResponseException(HttpStatusCodes.STATUS_CODE_SERVER_ERROR);
    setUpRegistryResponse(responseException);

    try {
      endpointCaller.call();
      Assert.fail("Call should have failed");

    } catch (ResponseException ex) {
      Assert.assertSame(responseException, ex);
    }
  }