@Override
    public Integer generateFinalResult(final Iterator<KeyValue<NullObject, Integer>> keyValues) {
        return keyValues.next().getValue();
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/clustering/peerpressure/ClusterCountMapReduce.java