@Override
  public int run(String[] args) throws IOException {
    JobConf conf = JobBuilder.parseInputAndOutput(this, getConf(), args);
    if (conf == null) {
      return -1;
    }

    conf.setMapperClass(StationMapper.class);
    conf.setMapOutputKeyClass(Text.class);
    conf.setReducerClass(MultipleOutputsReducer.class);
    conf.setOutputKeyClass(NullWritable.class);
    conf.setOutputFormat(NullOutputFormat.class); // suppress empty part file

    MultipleOutputs.addMultiNamedOutput(
        conf, "station", TextOutputFormat.class, NullWritable.class, Text.class);

    JobClient.runJob(conf);
    return 0;
  }