protected void handleSaslStartMessage() throws TTransportException, SaslException {
SaslClient saslClient = getSaslClient();
byte[] initialResponse = new byte[0];
if (saslClient.hasInitialResponse())
initialResponse = saslClient.evaluateChallenge(initialResponse);
LOGGER.debug("Sending mechanism name {} and initial response of length {}", mechanism,
initialResponse.length);
byte[] mechanismBytes = mechanism.getBytes();