fix minor styling issue

tests/fields/test_sequence_field.py

@@ -267,8 +267,8 @@ class TestSequenceField(MongoDBTestCase):
         foo = Foo(name="Foo")
         foo.save()
 
-        assert (
-            "base.counter" not in self.db["mongoengine.counters"].find().distinct("_id")
+        assert "base.counter" not in self.db["mongoengine.counters"].find().distinct(
+            "_id"
         )
         existing_counters = self.db["mongoengine.counters"].find().distinct("_id")
         assert "foo.counter" in existing_counters

tests/test_signals.py

@@ -58,7 +58,9 @@ class TestSignal(unittest.TestCase):
 
             @classmethod
             def post_save(cls, sender, document, **kwargs):
-                dirty_keys = list(document._delta()[0].keys()) + list(document._delta()[1].keys())
+                dirty_keys = list(document._delta()[0].keys()) + list(
+                    document._delta()[1].keys()
+                )
                 signal_output.append("post_save signal, %s" % document)
                 signal_output.append("post_save dirty keys, %s" % dirty_keys)
                 if kwargs.pop("created", False):