@Override
    public List<String> onTabComplete(CommandSender sender, Command command, String alias, String[] args) {
        String[] possiblities;
        String part;

        switch (args.length) {
            case 2:
                possiblities = new String[] { "one", "two" };
                part = args[1];
                break;
            case 6:
                possiblities = getWorldNames();
                part = args[5];
                break;
            case 1:
                if (sender instanceof Player) {
                    possiblities = getZoneNames(((Player) sender).getWorld().getName());
                    part = args[0];
                    break;
                }
            case 3:
            case 4:
            case 5:
            default:
                return new ArrayList<String>(0);
        }

        return checkPartialArgument(part, possiblities);
    }