code: private boolean handleRpcException(RpcException e, int attemptNumber)
              throws IOException {
          boolean tryPrivilegedPort = e.getStatus().equals(RejectStatus.AUTH_ERROR);
          boolean networkError = e.getStatus().equals(RpcStatus.NETWORK_ERROR);
          boolean retry = (tryPrivilegedPort || networkError) &&
                          ((attemptNumber + 1) < MOUNT_MAX_RETRIES);
          if (!retry) {
              String messageStart = networkError ? "network" : "rpc";
              String msg = String.format("%s error, server: %s, export: %s, RPC error: %s", messageStart, _server, _exportedPath,
                          e.getMessage());
              throw new MountException(MountStatus.MNT3ERR_IO, msg, e);
          }
          System.out.println("retry " + (attemptNumber + 1));
          if (tryPrivilegedPort) {
              LOG.info("Next try will be with a privileged port.");
          }
          return tryPrivilegedPort;
      }
docs: Decide whether to retry or throw an exception
  
  @param e
  The exception.
  @param attemptNumber
  The number of attempts so far.
  @return <ul><li><code>true</code> if there was an authentication failure and privileged ports should be tried,</li>
  <li><code>false</code> otherwise.</li></ul>
  @throws IOException