code: public void start() throws IOException
    {
      _process = _processBuilder.start();
      _out = new InputReader(new BufferedInputStream(_process.getInputStream()));
      _err = new InputReader(new BufferedInputStream(_process.getErrorStream()));
  
      _out.start();
      _err.start();
    }
docs: After creating the command, you have to start it...
  
  @throws IOException