code: public static void sortFile(File sortDir, File inputFile, File outputFile, Comparator<String> comparator,
                                  boolean skipHeader) {
          sortFile(sortDir, inputFile, outputFile, comparator, skipHeader, DEFAULT_MAX_BYTES, MERGE_FACTOR);
      }
docs: Sort a file, write sorted data to output file. Use the default max bytes size and the default merge factor.
  @param inputFile input file
  @param outputFile output file
  @param comparator comparator used to sort rows