PrintStream olderr = System.err;

        final Set<String> realms;
        if (classWorld != null) {
            realms = new HashSet<>();
            for (ClassRealm realm : classWorld.getRealms()) {
                realms.add(realm.getId());
            }
        } else {
            realms = Collections.emptySet();
        }

        try {
            if (stdout != null) {