/**
  * Returns if the server is online by checking the {@link IServerStatusService}.
  *
  * @return Returns if the server is online by checking the {@link IServerStatusService}.
  */
 private boolean isOnline() {
   try {
     ServerStatus status = serverStatusService.getServerStatus();
     if (ServerStatus.SERVER_ONLINE == status) {
       checkKey(status.getRegistrationIdsValidationKey());
       return true;
     }
     return false;
   } catch (Exception e) {
     return false;
   }
 }