code: public final String getDecodedString() throws TLVParserException {
          byte[] data = getContent();
          if (!(data.length > 0 && data[data.length - 1] == '\0')) {
              throw new TLVParserException("String must be null terminated");
          }
          try {
              return Util.decodeString(data, 0, data.length - 1);
          } catch (CharacterCodingException e) {
              throw new TLVParserException("Malformed UTF-8 data", e);
          }
      }
docs: Converts the TLV element content data to UTF-8 string.
  
  @return Decoded instance of string.
  
  @throws TLVParserException
  when content string isn't null terminated or is malformed UTF-8 data.