docs: public static String URLDecode( String str,
                                      String enc ) {
  
          if (str == null) {
              return (null);
          }
  
          // use the specified encoding to extract bytes out of the
          // given string so that the encoding is not lost. If an
          // encoding is not specified, let it use platform default
          byte[] bytes = null;
          try {
              if (enc == null) {
                  bytes = str.getBytes();
              } else {
                  bytes = str.getBytes(enc);
              }
          } catch (UnsupportedEncodingException uee) {
          }
  
          return URLDecode(bytes, enc);
  
      }