new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  import os
  
  os.system('python nettacker.py --help')
  os.system("python nettacker.py -i 127.0.0.1 -u user1,user2 -p pass1,pass2 -m all -g 21,25,80,443 -t 2")
  
subject: add travis ci script for testing all functions