old_contents: #!/usr/bin/env python
  import django_prometheus
  import unittest
  
  
  # TODO(korfuri): Add real tests. For now, this is just a placeholder
  # to set up a testing system.
  class DjangoPrometheusTest(unittest.TestCase):
      def testNothing(self):
          self.assertTrue(True)
  
  
  if __name__ == 'main':
      unittest.main()
  
new_contents: #!/usr/bin/env python
  import django_prometheus
  from django_prometheus.utils import PowersOf, _INF
  import unittest
  
  
  class DjangoPrometheusTest(unittest.TestCase):
      def testPowersOf(self):
          """Tests utils.PowersOf."""
          self.assertEqual(
              [0, 1, 2, 4, 8, _INF],
              PowersOf(2, 4))
          self.assertEqual(
              [0, 3, 9, 27, 81, 243, _INF],
              PowersOf(3, 5, lower=1))
          self.assertEqual(
              [1, 2, 4, 8, _INF],
              PowersOf(2, 4, include_zero=False))
          self.assertEqual(
              [4, 8, 16, 32, 64, 128, _INF],
              PowersOf(2, 6, lower=2, include_zero=False))
  
  
  if __name__ == 'main':
      unittest.main()
  
subject: Add a test for PowersOf.