HttpRequest* request = new HttpRequest();
request->setUrl("http://just-make-this-request-failed.com");
request->setRequestType(HttpRequest::Type::GET);
request->setResponseCallback(this, httpresponse_selector(HttpClientTest::onHttpRequestCompleted));
This code is from the NetworkTest of cocos2d-x 3.0. I don't understand why I should pass Layer* to setResponseCallback? What if I want to send/get request/response without creating a single layer? Why shouldn't I be able to do that?