public static void main(String[] args) {
   ExecuteResult result = ExecuteCmdUtils.executeCmd("cd /home/machen && python hello.py");
   System.out.println(result.getExitCode());
   System.out.println(result.getReturnString());
   System.out.println(result.getStartTime().toString());
   System.out.println(result.getEndTime().toString());
 }