code: public void save(String fileName)
        throws FileNotFoundException, UnsupportedEncodingException {
      try (PrintWriter writer = new PrintWriter(fileName, "UTF-8")) {
        for (Map.Entry<String, Integer> entry : data.entrySet()) {
          writer.println(String.format("%d;%s", entry.getValue(), entry.getKey()));
        }
      }
    }
docs: Save the abbreviations into a file.
  
  @param fileName The file name.
  
  @throws FileNotFoundException
  @throws UnsupportedEncodingException