code: protected void addDocIterators(Collection<Iterator<Document>> docIters,
                                     String[] fileNames) throws IOException {
          boolean removeHeader = argOptions.hasOption('H');
          for (String s : fileNames)
            docIters.add(
                new DependencyFileDocumentIterator(s, removeHeader));
      }
  
      /**
       * Prints out information on how to run the program to {@code stdout} using
       * the option descriptions for compound words, tokenization, .sspace formats
       * and help.
       */
      @Override protected void usage() {
          String specifics = getAlgorithmSpecifics();
          System.out.println(
              "usage: java " 
              + this.getClass().getName()
              + " [options] <output-dir>\n"
              + argOptions.prettyPrint() 
              + ((specifics.length() == 0) ? "" : "\n" + specifics)
              + "\n\n" + OptionDescriptions.TOKEN_FILTER_DESCRIPTION
              + "\n\n" + OptionDescriptions.TOKEN_STEMMING_DESCRIPTION
              + "\n\n" + OptionDescriptions.FILE_FORMAT_DESCRIPTION
              + "\n\n" + DEPENDENCY_EXTRACTOR_DESCRIPTION
              + "\n\n" + OptionDescriptions.HELP_DESCRIPTION);
      }
  }
docs: Adds a {@link DependencyFileDocumentIterator} to {@code docIters} for
  each file name provided.