@Override
 protected void map(Centroid key, IntWritable value, Context context)
     throws IOException, InterruptedException {
   context.write(new Text(key.toString()), new Text(value.toString()));
 }
 @Override
 protected void map(Centroid key, Point value, Context context)
     throws IOException, InterruptedException {
   String out = key.toString() + " " + value.toString();
   context.write(new Text(out), new Text(""));
 }