@Override
            public void getConfig(ProtonConfig.Builder builder) {
                if (concurrency != null) {
                    builder.feeding.concurrency(concurrency);
                }
                if (niceness != null) {
                    builder.feeding.niceness(niceness);
                }
            }
Class representing the tuning config used for a search cluster.
Take a look at proton.def and vespa doc for detailed explanations.

@author geirst
config-model/src/main/java/com/yahoo/vespa/model/search/Tuning.java