new_contents: from itertools import combinations
  from unittest import TestCase
  
  from ordering import Ordering
  
  
  class TestComparisons(TestCase):
      def setUp(self) -> None:
          self.ordering = Ordering[int]()
  
          self.ordering.insert_start(0)
          self.ordering.insert_after(0, 1)
          self.ordering.insert_before(0, 2)
          self.ordering.insert_end(3)
          self.ordering.insert_start(4)
          self.ordering.insert_after(3, 5)
          self.ordering.insert_before(3, 6)
  
          self.ordering_list = [4, 2, 0, 1, 6, 3, 5]
  
      def test_iterate_correct_order(self) -> None:
          self.assertListEqual(
              list(self.ordering),
              self.ordering_list
          )
  
      def test_comparisons(self) -> None:
          for a, b in combinations(self.ordering_list, 2):
              self.assertTrue(self.ordering.compare(a, b))
              self.assertFalse(self.ordering.compare(b, a))
  
subject: Add unit test for complicated comparisons