Greeting greeting = new Greeting(greetingResponse.getEntity().data().copy());
final String NEW_MESSAGE = "This is a new message!";
greeting.setMessage(NEW_MESSAGE);
Request<EmptyRecord> writeRequest = builders.update().id(1L).input(greeting).build();
restClient.sendRequest(writeRequest).getResponse();
// GET again, to verify that our POST worked.
Request<Greeting> request2 = builders.get().id(1L).build();
ResponseFuture<Greeting> future2 = restClient.sendRequest(request2);
greetingResponse = future2.get();