  
          for test in extra_tests:
              suite.addTest(test)
  
          return reorder_suite(suite, self.reorder_by)
  
      def setup_databases(self, **kwargs):
          return setup_databases(self.verbosity, self.interactive, self.keepdb, **kwargs)
  
      def run_suite(self, suite, **kwargs):
 
</s> remove def reorder_suite(suite, classes):
 </s> add def reorder_suite(suite, classes, reverse=False): </s> remove             help='Preserve the test DB between runs. Defaults to False')
 </s> add             help='Preserves the test DB between runs.')
        parser.add_argument('-r', '--reverse', action='store_true', dest='reverse',
            default=False,
            help='Reverses test cases order.') </s> remove     partition_suite(suite, classes, bins)
 </s> add     partition_suite(suite, classes, bins, reverse=reverse) </s> remove                  verbosity=1, interactive=True, failfast=False, keepdb=False,
 </s> add                  verbosity=1, interactive=True, failfast=False, keepdb=False, reverse=False, </s> remove def django_tests(verbosity, interactive, failfast, keepdb, test_labels):
 </s> add def django_tests(verbosity, interactive, failfast, keepdb, reverse, test_labels):
        return reorder_suite(suite, self.reorder_by, self.reverse)
  
          for test in extra_tests:
              suite.addTest(test)
  
        return reorder_suite(suite, self.reorder_by, self.reverse)
  
      def setup_databases(self, **kwargs):
          return setup_databases(self.verbosity, self.interactive, self.keepdb, **kwargs)
  
      def run_suite(self, suite, **kwargs):
keep keep keep keep replace keep keep keep keep keep
 Fixed #23742 -- Added an option to reverse tests order.

This is useful for debugging side effects affecting tests that
are usually executed before a given test. Full suite and pair
tests sort cases more or less deterministically, thus some test
cross-dependencies are easier to reveal by reversing the order.

Thanks Preston Timmons for the review. 
django/test/runner.py