public void reduce(
        IntPair key,
        Iterator<NullWritable> values,
        OutputCollector<IntPair, NullWritable> output,
        Reporter reporter)
        throws IOException {

      /*[*/ output.collect(key, NullWritable.get()); /*]*/
    }
    public void map(
        LongWritable key,
        Text value,
        OutputCollector<IntPair, NullWritable> output,
        Reporter reporter)
        throws IOException {

      parser.parse(value);
      if (parser.isValidTemperature()) {
        /*[*/ output.collect(
            new IntPair(parser.getYearInt(), +parser.getAirTemperature()),
            NullWritable.get()); /*]*/
      }
    }
    @SuppressWarnings("unchecked")
    public void reduce(
        Text key,
        Iterator<Text> values,
        OutputCollector<NullWritable, Text> output,
        Reporter reporter)
        throws IOException {

      OutputCollector collector =
          multipleOutputs.getCollector("station", key.toString().replace("-", ""), reporter);
      while (values.hasNext()) {
        collector.collect(NullWritable.get(), values.next());
      }
    }