private void updateWithNewConfig(RawConfig newConfig) {
        log.log(Level.FINE, () -> "config to be returned for '" + newConfig.getKey() +
                                  "', generation=" + newConfig.getGeneration() +
                                  ", payload=" + newConfig.getPayload());
        memoryCache.update(newConfig);
        updateSubscribers(newConfig);
    }
Updates subscribers with new config. This method will be called when a response with changed config is
received from upstream (content or generation has changed) or the server timeout has elapsed.

@param config new config
config-proxy/src/main/java/com/yahoo/vespa/config/proxy/RpcConfigSourceClient.java