code: public static String cleanup(String sequence) {
      String result = sequence.replaceAll("\\s", ""); // remove all white
      // space
      if (result.equals(result.toLowerCase())) {
        result = result.toUpperCase();
      }
      return result;
    }
docs: remove white space, and convert all lower case to upper case
  
  @param sequence given sequence
  @return cleaned sequence without withspace and all characters are in uppercase