presto-plugin-toolkit/src/main/java/io/prestosql/plugin/base/authentication/KerberosTicketUtils.java/KerberosTicketUtils/isTicketGrantingServerPrincipal
class KerberosTicketUtils:    private static boolean isTicketGrantingServerPrincipal(KerberosPrincipal principal)
    {
        if (principal == null) {
            return false;
        }
        if (principal.getName().equals("krbtgt/" + principal.getRealm() + "@" + principal.getRealm())) {
            return true;
        }
        return false;
    }