code: public String hyphenate(String word, String separator, boolean allowContextChanges) {
          requireValidHandle();
          if (!isValidInput(word) || !isValidInput(separator)) {
              return word;
          }
          ByteArray cHyphenated = getLib().voikkoInsertHyphensCstr(
                  handle, s2n(word), s2n(separator), boolToInt(allowContextChanges));
          String hyphenated = cHyphenated.toString();
          getLib().voikkoFreeCstr(cHyphenated);
          return hyphenated;
      }
docs: A convenience function that uses getHyphenationPattern and returns the word in
  hyphenated form. For example, in order to insert soft hyphens for automatic hyphenation
  in HTML text use hyphenate(word, "&shy;", false)
  @param word The word to be hypnenated
  @param separtor The separator to be inserted at hyphenation point
  @param allowContextChanges Whether to allow hyphenation at points where inserting
  the hyphen will lead to other changes in the word
  @return the given word in fully hyphenated form.