@Override
 public void onDisable() {
   log.info("Shutting down blockqueue and undothread, please wait.");
   bq.shouldrun = false;
   while (bq.isAlive()) {
     // wait
   }
   ut.shouldRun = false;
   while (ut.isAlive()) {
     // wait
   }
   log.info("WorldThreadit Disabled.");
 }
 @Override
 public void onEnable() {
   WorldThreadit.plugin = this;
   log = getLogger();
   getServer().getPluginManager().registerEvents(new WorldThreadit(), this);
   bq = new BlockQueue(this);
   bq.start();
   ut = new UndoThread(this);
   ut.start();
   log.info("WorldThreadit enabled!");
   getCommand("wt").setExecutor(new BaseCommandExecutor(this));
 }