private boolean loadWorld(CommandSender sender, String[] args) {
   if (args != null && args.length == 1) {
     WorldBase base = plugin.worldBases.get(args[0]);
     if (base != null) {
       WorldInstance instance = plugin.launchInstance(base, true);
       if (instance != null && sender instanceof Player) {
         Player player = (Player) sender;
         plugin.playerLocations.put(player.getName().toLowerCase(), instance.getWorldName());
         instance.teleport(player);
       }
     }
   }
   return true;
 }
  private boolean newWorld(CommandSender sender, String[] args) {
    if (args.length < 3) {
      return false;
    }

    String worldName = args[0];
    if (!worldName.matches("^[A-Za-z0-9_]+$")) {
      return false;
    }

    String seed = args[1];
    if (!seed.matches("[0-9]+")) {
      return false;
    }

    String worldDesc = args[2];
    for (int i = 3; i < args.length; i++) {
      worldDesc += " " + args[i];
    }

    sender.sendMessage("Creating new world base...");

    Configuration config = plugin.getConfig();
    ConfigurationSection section = config.createSection("worlds." + worldName);
    section.set("folder", worldName);
    section.set("description", worldDesc);
    section.set("seed", Long.parseLong(seed));
    plugin.saveConfig();

    WorldBase base = new WorldBase(worldName, section);
    plugin.worldBases.put(worldName, base);

    WorldInstance instance = new WorldInstance(base, true, true);
    plugin.loadedWorlds.put(instance.getWorldName(), instance);
    if (sender instanceof Player) {
      instance.teleport((Player) sender);
    }

    sender.sendMessage("New world base created!");
    return true;
  }