use assert[Not]In where appropriate
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index f05bd96..f456226 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -231,8 +231,7 @@
         b = self.type2test(b"abc")
         self.assertIn(ord('a'), b)
         self.assertIn(int(ord('a')), b)
-        self.assertFalse(200 in b)
-        self.assertFalse(200 in b)
+        self.assertNotIn(200, b)
         self.assertRaises(ValueError, lambda: 300 in b)
         self.assertRaises(ValueError, lambda: -1 in b)
         self.assertRaises(TypeError, lambda: None in b)
@@ -246,10 +245,10 @@
             self.assertIn(f(b"ab"), b)
             self.assertIn(f(b"bc"), b)
             self.assertIn(f(b"abc"), b)
-            self.assertFalse(f(b"ac") in b)
-            self.assertFalse(f(b"d") in b)
-            self.assertFalse(f(b"dab") in b)
-            self.assertFalse(f(b"abd") in b)
+            self.assertNotIn(f(b"ac"), b)
+            self.assertNotIn(f(b"d"), b)
+            self.assertNotIn(f(b"dab"), b)
+            self.assertNotIn(f(b"abd"), b)
 
     def test_fromhex(self):
         self.assertRaises(TypeError, self.type2test.fromhex)