old_contents: import unittest
  from primes import is_prime
  
  class PrimesTestCase(unittest.TestCase):
      """Tests for `primes.py`."""
  
      def test_is_five_prime(self):
          """Is five successfully determined to be prime?"""
          self.assertTrue(is_prime(5))
  
  if __name__ == '__main__':
      unittest.main()
new_contents: import unittest
  from pydefm import plusone
  
  class PrimesTestCase(unittest.TestCase):
      """Tests for `primes.py`."""
  
      def test_is_five_prime(self):
          """Is five successfully determined to be prime?"""
          self.assertTrue(plusone.is_prime(5))
  
  if __name__ == '__main__':
      unittest.main()
subject: fix bug in test