use assert[Not]IsInstance where appropriate
diff --git a/Lib/test/test_hash.py b/Lib/test/test_hash.py
index 18ec04e..d2571d0 100644
--- a/Lib/test/test_hash.py
+++ b/Lib/test/test_hash.py
@@ -105,11 +105,11 @@
         objects = (self.default_expected +
                    self.fixed_expected)
         for obj in objects:
-            self.assertTrue(isinstance(obj, Hashable), repr(obj))
+            self.assertIsInstance(obj, Hashable)
 
     def test_not_hashable(self):
         for obj in self.error_expected:
-            self.assertFalse(isinstance(obj, Hashable), repr(obj))
+            self.assertNotIsInstance(obj, Hashable)
 
 
 # Issue #4701: Check that some builtin types are correctly hashable