use assert[Not]In where appropriate
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 69f31a0..fac0728 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -1628,8 +1628,8 @@
             self.assertEqual(v1, v2)
 
     def test_equality_with_other_types(self):
-        self.assertTrue(Decimal(10) in ['a', 1.0, Decimal(10), (1,2), {}])
-        self.assertTrue(Decimal(10) not in ['a', 1.0, (1,2), {}])
+        self.assertIn(Decimal(10), ['a', 1.0, Decimal(10), (1,2), {}])
+        self.assertNotIn(Decimal(10), ['a', 1.0, (1,2), {}])
 
     def test_copy(self):
         # All copies should be deep