code: public Job createJob (FileSystemDataset dataset) throws IOException {
      configurator = CompactionJobConfigurator.instantiateConfigurator(this.state);
      return configurator.createJob(dataset);
    }
docs: Constructs a map-reduce job suitable for compaction. The detailed format-specific configuration
  work is delegated to {@link CompactionJobConfigurator#createJob(FileSystemDataset)}
  
  @param  dataset a top level input path which contains all files those need to be compacted
  @return a map-reduce job which will compact files against {@link org.apache.gobblin.dataset.Dataset}