Silence BytesWarning while testing exception
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 159fd8a..35c7f51 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -572,7 +572,8 @@
                          "%s" % result)
         self.assertRaises((TypeError, AttributeError), urllib.parse.unquote, None)
         self.assertRaises((TypeError, AttributeError), urllib.parse.unquote, ())
-        self.assertRaises((TypeError, AttributeError), urllib.parse.unquote, b'')
+        with support.check_warnings(('', BytesWarning), quiet=True):
+            self.assertRaises((TypeError, AttributeError), urllib.parse.unquote, b'')
 
     def test_unquoting_badpercent(self):
         # Test unquoting on bad percent-escapes