code: @Override
      public SortField[] sortFields() {
          return new SortField[]{new SortField(FIELD_NAME, new FieldComparatorSource() {
              @Override
              public FieldComparator<?> newComparator(String field,
                                                      int hits,
                                                      int sort,
                                                      boolean reversed) throws IOException {
                  return new TokenMapperGenericSorter(TokenMapperGeneric.this, hits, field);
              }
          })};
      }
docs: {@inheritDoc}