code: public static String fixUmlauts(String string) {
          String s1 = StringUtils.replace(string, "ä", "ae");
          String s2 = StringUtils.replace(s1, "ö", "oe");
          String s3 = StringUtils.replace(s2, "ü", "ue");
          String s4 = StringUtils.replace(s3, "ß", "ss");
  
          return s4;
      }
docs: replace umlauts to be in compliance with  RFC 3986 URLs
  
  @param string that may contain umlauts
  @return clean string