code: public void format(PatriciaTrie<V> trie, File file) throws FileNotFoundException {
          format(trie, file, false);
      }
docs: Format trie and write to file
  
  @param trie  trie to format
  @param file  file to write to
  @throws FileNotFoundException if the file exists but is a directory rather than a regular file,
  does not exist but cannot be created, or cannot be opened for any other reason