public static AuthenticationResponse refreshAccessToken(Account account) {
Gson gson = new Gson();
StringBuilder response = null;
try {
URL url = new URL("https://authserver.mojang.com/refresh");
String request = gson.toJson(new RefreshRequest(account.getAccessToken(), account.getClientToken()));
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setConnectTimeout(15000);
connection.setReadTimeout(15000);
connection.setRequestMethod("POST");