code: public String decode(byte[] cidbytes, final int offset, final int len){
          StringBuffer sb = new StringBuffer(); // it's a shame we can't make this StringBuilder
          for(int i = offset; i < offset + len; i++){
              String rslt = decodeSingleCID(cidbytes, i, 1);
              if (rslt == null){
                  rslt = decodeSingleCID(cidbytes, i, 2);
                  i++;
              }
              sb.append(rslt);
          }
  
          return sb.toString();
      }
docs: Decodes a string of bytes (encoded in the font's encoding) into a unicode string
  This will use the ToUnicode map of the font, if available, otherwise it uses
  the font's encoding
  @param cidbytes    the bytes that need to be decoded
  @return  the unicode String that results from decoding
  @since 2.1.7