private static final Logger logger = LogManager.getLogger(SpnegoAuthenticator.class);

    protected static final String SPNEGO_INITIALIZED = "spnego.initialized";
    protected static final String SPNEGO_EXCLUDE_DIRS = "spnego.exclude.dirs";
    protected static final String SPNEGO_ALLOW_DELEGATION = "spnego.allow.delegation";
    protected static final String SPNEGO_ALLOW_LOCALHOST = "spnego.allow.localhost";