test.cpp

void main()
{
  /// Old way
  NetworkManager::urlFetch(QUrl("google.com"), [](auto reply) {
    // do shit with reply
  });
  // or
  NetworkManager::urlFetch(QNetworkRequest("google.com"), [](auto reply) {
    // do shit with reply
  });
  // or
  NetworkManager::urlFetch(QUrl("google.com"), caller,
  [](auto reply) {
    // do shit with reply on finished
  },
  [](auto reply) {
    // do initial shit with reply
  });
  
  /// New way
  NetworkRequest req("google.com");
  // or NetworkRequest req("google.com", caller);
  req.onReplyCreated = [](auto reply) {
    // handle when the reply is created
  };
  req.start([](auto reply) {
    // on reply finished
  });
}