LOG.debug("handleUpstream: Responding to server's token of length: " +
serverToken.getSaslToken().length);
}
// Generate SASL response (but we only actually send the response if it's
// non-null.
byte[] responseToServer = saslNettyClient.saslResponse(serverToken);
if (responseToServer == null) {
// If we generate a null response, then authentication has completed (if
// not, warn), and return without sending a response back to the server.
if (LOG.isDebugEnabled()) {
LOG.debug("handleUpstream: Response to server is null: " +