old_contents: """Hello world application."""
  
  
  import webapp2
  
  
  class MainPage(webapp2.RequestHandler):
  
      def get(self):
          self.response.headers['Content-Type'] = 'text/plain'
          self.response.write('Hello, webapp2 World!')
  
  
  APP = webapp2.WSGIApplication([
      ('/', MainPage),
  ], debug=True)
  
new_contents: """Hello world application."""
  
  
  import webapp2
  
  
  class MainPage(webapp2.RequestHandler):
  
      def get(self):
          self.response.headers['Content-Type'] = 'text/plain'
          self.response.write('Hello, Hassaan World!')
  
  
  APP = webapp2.WSGIApplication([
      ('/', MainPage),
  ], debug=True)
  
subject: Test Uploading