private boolean newConfigOrException() {
        // These flags may have been left true from a previous call, since ConfigSubscriber's nextConfig
        // not necessarily returned true and reset the flags then
        ConfigState<T> configState = getConfigState();
        return configState.isGenerationChanged() || configState.isConfigChanged() || hasException();
    }
A queue containing responses (requests that got a callback from JRT) that has not yet been handled.
config/src/main/java/com/yahoo/config/subscription/impl/JRTConfigSubscription.java