@Override
 public void setToken(String token) {
   try {
     if (!jmxHelper.isConnected()) jmxHelper.connect();
     ;
     jmxHelper.operation(storageServiceMBean, "move", token);
     log.info("Moved server {} to token {}", getId(), token);
   } catch (IOException ioe) {
     Throwables.propagate(ioe);
   }
 }