public int threadsPerSearch() {
        if (searchNode == null) return 1;
        if (searchNode.threads == null) return 1;
        if (searchNode.threads.numThreadsPerSearch == null) return 1;
        return searchNode.threads.numThreadsPerSearch;
    }
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