@Override
    public SaslNegotiator newSaslNegotiator(final InetAddress remoteAddress) {
        logger.debug("newSaslNegotiator() called");
        return Subject.doAs(subject, (PrivilegedAction<SaslNegotiator>) Krb5SaslAuthenticator::new);
    }
Called once on server startup with the authentication.config from the *.yaml file
gremlin-server/src/main/java/org/apache/tinkerpop/gremlin/server/auth/Krb5Authenticator.java