old_contents: from proso.django.test import TestCase
  from models import Comment, Rating
  import json
  
  
  class FeedbackAPITest(TestCase):
  
      def testComment(self):
          # invalid e-mail address
          response = self.client.post('/feedback/feedback/', json.dumps({
              'email': 'aaa',
              'text': 'dummy'
          }), content_type='application/json')
          self.assertEqual(response.status_code, 400, "User can't give a feedback with invalid e-mail address.")
          # empty e-mail address
          response = self.client.post('/feedback/feedback/', json.dumps({
              'text': 'dummy with empty e-mail'
          }), content_type='application/json')
          self.assertEqual(response.status_code, 201, "User can give a feedback with empty e-mail address.")
          self.assertEqual(Comment.objects.all().count(), 1, "The feedback comment from user is saved.")
          # valid e-mail address
          response = self.client.post('/feedback/feedback/', json.dumps({
              'email': 'test@test.com',
              'text': 'dummy with valid e-mail'
          }), content_type='application/json')
          self.assertEqual(response.status_code, 201, "User can give a feedback with valid e-mail address.")
          self.assertEqual(Comment.objects.all().count(), 2, "The feedback comment from user is saved.")
  
      def testRating(self):
          # invalid value
          response = self.client.post('/feedback/rating/', json.dumps({
              'value': 4
          }), content_type='application/json')
          self.assertEqual(response.status_code, 400, "User can't give a rating with invalid value.")
          # valid value
          response = self.client.post('/feedback/rating/', json.dumps({
              'value': 3
          }), content_type='application/json')
          self.assertEqual(response.status_code, 201, "User can give a rating with invalid value.")
          self.assertEqual(Rating.objects.all().count(), 1, "The rating from user is saved.")
  
new_contents: from proso.django.test import TestCase
  from models import Comment, Rating
  import json
  
  
  class FeedbackAPITest(TestCase):
  
      def testComment(self):
          # empty e-mail address
          response = self.client.post('/feedback/feedback/', json.dumps({
              'text': 'dummy with empty e-mail'
          }), content_type='application/json')
          self.assertEqual(response.status_code, 201, "User can give a feedback with empty e-mail address.")
          self.assertEqual(Comment.objects.all().count(), 1, "The feedback comment from user is saved.")
          # valid e-mail address
          response = self.client.post('/feedback/feedback/', json.dumps({
              'email': 'test@test.com',
              'text': 'dummy with valid e-mail'
          }), content_type='application/json')
          self.assertEqual(response.status_code, 201, "User can give a feedback with valid e-mail address.")
          self.assertEqual(Comment.objects.all().count(), 2, "The feedback comment from user is saved.")
  
      def testRating(self):
          # invalid value
          response = self.client.post('/feedback/rating/', json.dumps({
              'value': 4
          }), content_type='application/json')
          self.assertEqual(response.status_code, 400, "User can't give a rating with invalid value.")
          # valid value
          response = self.client.post('/feedback/rating/', json.dumps({
              'value': 3
          }), content_type='application/json')
          self.assertEqual(response.status_code, 201, "User can give a rating with invalid value.")
          self.assertEqual(Rating.objects.all().count(), 1, "The rating from user is saved.")
  
subject: remove obsolete test