new_contents: import unittest
  
  import mock
  
  from celery_janitor.utils import Config
  
  
  class ConfigTest(unittest.TestCase):
  
      @mock.patch('celery_janitor.utils.conf.BROKER_URL', 'sqs://aws_access_key_id:aws_secret@')
      def test_sqs_backend(self):
          self.config = Config()
          backend = self.config.get_backend()
          self.assertEqual(backend, 'celery_janitor.backends.sqs.SQSBackend')
          key, secret = self.config.get_credentials()
          self.assertEqual(key, 'aws_access_key_id')
          self.assertEqual(secret, 'aws_secret')
  
subject: Add test