old_contents: from dasem.app import app
  app.run(debug=True)
  
new_contents: from dasem.app import app
  
  # WSGIServer server better than werkzeug
  # http://stackoverflow.com/questions/37962925/
  from gevent.wsgi import WSGIServer
  http_server = WSGIServer(('', 5000), app)
  http_server.serve_forever()
  
subject: Change server