@Override
    public void cleanup(final Reducer<ObjectWritable, ObjectWritable, ObjectWritable, ObjectWritable>.Context context) {
        this.mapReduce.workerEnd(MapReduce.Stage.REDUCE);
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
hadoop-gremlin/src/main/java/org/apache/tinkerpop/gremlin/hadoop/process/computer/HadoopReduce.java