def test_iterator_to_list():
  """Test the iterator_to_list function."""
  my_set = OrderedSet()
  my_set.append(1)
  my_set.append(2)
  my_set.append(3)
  expected = [1, 2, 3]
  my_list = iterator_to_list(my_set)
  assert_equal(type(my_list), type(expected), 'Expected the result to be a list.')
  assert_equal(my_list, expected)
 def test_length(self):
   """Test the __length__ method of OrderedSet."""
   my_set = OrderedSet()
   assert_equal(len(my_set), 0)
   my_set.append(1)
   assert_equal(len(my_set), 1)
   my_set.prepend(2)
   assert_equal(len(my_set), 2)
   my_set.insert_after(1, 3)
   assert_equal(len(my_set), 3)
   my_set.remove(2)
   assert_equal(len(my_set), 2)    
 def create_basic_set(self):
   my_set = OrderedSet()
   my_set.append(1)
   my_set.append(2)
   my_set.append(3)
   return my_set