old_contents: from twisted.trial import unittest
  
  from better_od import OrderedSet
  
  
  class TestOrderedDict(unittest.TestCase):
      def setUp(self):
          self.values = 'abcddefg'
          self.s = OrderedSet(self.values)
  
      def test_order(self):
          expected = list(enumerate('abcdefg'))
          self.assertEquals(list(enumerate(self.s)), expected)
  
      def test_index(self):
          self.assertEquals(self.s.key_index('c'), 2)
  
      def test_add_new_value(self):
          prev = len(self.s)
          self.s.add('z')
          self.assertEqual(len(self.s), prev + 1)
  
new_contents: from twisted.trial import unittest
  
  from better_od import OrderedSet
  
  
  class TestOrderedSet(unittest.TestCase):
      def setUp(self):
          self.values = 'abcddefg'
          self.s = OrderedSet(self.values)
  
      def test_order(self):
          expected = list(enumerate('abcdefg'))
          self.assertEquals(list(enumerate(self.s)), expected)
  
      def test_index(self):
          self.assertEquals(self.s.key_index('c'), 2)
  
  
  class TestOrderedSetMutations(unittest.TestCase):
      def test_add_new_value(self):
          prev = len(self.s)
          self.s.add('z')
          self.assertEqual(len(self.s), prev + 1)
  
subject: Rename tests.test_OrderedSet test cases. Add TestOrderedSetMutations test suite.