docs: private void pumpInputData() throws IOException {
      for (Input input : inputs) {
        if (input.pump == null) {
          continue;
        }
        OutputStream os;
        if (input.pipeName.equals(STDIN_FILE_NAME)) {
          os = process.getOutputStream();
        } else {
          throw new IOException("Only stdin piping is supported so far.");
        }
        input.pump.pump(os);
      }
    }