Combiner<IntWritable, IntWritable> combiner =
new MinimumIntCombiner();
IntWritable vertexId = new IntWritable(1);
IntWritable result = combiner.createInitialMessage();
combiner.combine(vertexId, result, new IntWritable(39947466));
combiner.combine(vertexId, result, new IntWritable(199));
combiner.combine(vertexId, result, new IntWritable(42));
combiner.combine(vertexId, result, new IntWritable(19998888));
assertEquals(42, result.get());
}