code: private int setSafeMode(boolean safeMode) throws IOException {
      // Get the current configuration
      CoronaConf conf = new CoronaConf(getConf());
  
      InetSocketAddress address = NetUtils.createSocketAddr(conf
        .getClusterManagerAddress());
      TFramedTransport transport = new TFramedTransport(
        new TSocket(address.getHostName(), address.getPort()));
      ClusterManagerService.Client client = new ClusterManagerService.Client(
        new TBinaryProtocol(transport));
  
      try {
        transport.open();
        if (client.setSafeMode(safeMode)) {
          System.out.println("The safeMode is: " +
                              (safeMode ? "ON" : "OFF"));
        } else {
          System.err.println("Could not set the safeMode flag");
        }
      } catch (TException e) {
        throw new IOException(e);
      }
  
      return 0;
    }
docs: Turns on the Safe Mode if safeMode is true. Turns off the Safe Mode if
  safeMode is false.
  @param safeMode Is true if we want the Safe Mode to be on. false
  otherwise.
  @return 0 if successful.
  @throws IOException