code: @Override
      public int compare(Row row1, Row row2) {
          Columns columns1 = rowMapper.columns(row1);
          Columns columns2 = rowMapper.columns(row2);
          return comparatorChain.compare(columns1, columns2);
      }
docs: {@inheritDoc}
  
  @param row1 A {@link Row}.
  @param row2 A {@link Row}.
  @return A negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater
  than the second according to a Lucene {@link Sort}.