code: public static String[] delimitedListToStringArray(@Nullable final String str,
        @Nullable final String delimiter) {
      return StringUtils.delimitedListToStringArray(str, delimiter, null);
    }
docs: Take a {@code String} that is a delimited list and convert it into a {@code String} array.
  <p>
  A single {@code delimiter} may consist of more than one character, but it will still be
  considered as a single delimiter string, rather than as bunch of potential delimiter
  characters, in contrast to {@link #tokenizeToStringArray}.
  
  @param str the input {@code String}
  @param delimiter the delimiter between elements (this is a single delimiter, rather than a
  bunch individual delimiter characters)
  @return an array of the tokens in the list
  @see #tokenizeToStringArray