Kerb5Authenticator.cloneInternal(to, from);
        to.serviceName = from.serviceName;
        to.configuration = from.configuration;
        to.cachedSubject = from.cachedSubject;
    }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.smb.Kerb5Authenticator#refresh()
     */
    @Override