code: private void setup() {
          super.setMapperClass(Mapper.class);
          super.setMapOutputKeyClass(Key.class);
          super.setMapOutputValueClass(Value.class);
  
          super.setPartitionerClass(SimplePartitioner.class);
          super.setGroupingComparatorClass(SimpleGroupingComparator.class);
          super.setSortComparatorClass(SimpleSortComparator.class);
  
          super.setReducerClass(Reducer.class);
          super.setOutputKeyClass(Key.class);
          super.setOutputValueClass(Value.class);
      }
docs: Default job settings.