bpo-37685: Use singletons ALWAYS_EQ and NEVER_EQ in more tests. (GH-15167)

diff --git a/Lib/test/test_contains.py b/Lib/test/test_contains.py
index 036a1d0..471d04a 100644
--- a/Lib/test/test_contains.py
+++ b/Lib/test/test_contains.py
@@ -1,5 +1,6 @@
 from collections import deque
 import unittest
+from test.support import NEVER_EQ
 
 
 class base_set:
@@ -69,13 +70,7 @@
         # containment and equality tests involving elements that are
         # not necessarily equal to themselves
 
-        class MyNonReflexive(object):
-            def __eq__(self, other):
-                return False
-            def __hash__(self):
-                return 28
-
-        values = float('nan'), 1, None, 'abc', MyNonReflexive()
+        values = float('nan'), 1, None, 'abc', NEVER_EQ
         constructors = list, tuple, dict.fromkeys, set, frozenset, deque
         for constructor in constructors:
             container = constructor(values)