code: public static void write(final String fileName, final Formula formula, boolean alignLiterals) throws IOException {
      write(new File(fileName.endsWith(".dot") ? fileName : fileName + ".dot"), formula, alignLiterals);
    }
docs: Writes a given formula's internal data structure as a dot file.
  @param fileName      the file name of the dot file to write
  @param formula       the formula
  @param alignLiterals indicates whether all literals should be aligned at the same vertical level
  @throws IOException if there was a problem writing the file