code: public void
  setTSIG(TSIG key, int error, TSIGRecord querytsig) {
  	this.tsigkey = key;
  	this.tsigerror = error;
  	this.querytsig = querytsig;
  }
docs: Sets the TSIG key and other necessary information to sign a message.
  @param key The TSIG key.
  @param error The value of the TSIG error field.
  @param querytsig If this is a response, the TSIG from the request.