@Override
public SocialUser processCallback(ClientSessionModel clientSession, SocialProviderConfig config, AuthCallback callback) throws SocialProviderException {
String error = callback.getQueryParam(OAuth2Constants.ERROR);
if (error != null) {
throw new SocialAccessDeniedException();
}
String id = callback.getQueryParam("id");
String username = callback.getQueryParam("username");
SocialUser user = new SocialUser(id, username);