diff --git a/pydantic/utils.py b/pydantic/utils.py
index d692f4f..d14a285 100644
--- a/pydantic/utils.py
+++ b/pydantic/utils.py
@@ -241,7 +241,8 @@ def unique_list(input_list: Union[List[T], Tuple[T, ...]]) -> List[T]:
 
 
 def update_normalized_all(
-    item: Union['AbstractSetIntStr', 'MappingIntStrAny'], all_items: Union['AbstractSetIntStr', 'MappingIntStrAny'],
+    item: Union['AbstractSetIntStr', 'MappingIntStrAny'],
+    all_items: Union['AbstractSetIntStr', 'MappingIntStrAny'],
 ) -> Union['AbstractSetIntStr', 'MappingIntStrAny']:
     """
     Update item based on what all items contains.
diff --git a/tests/requirements.txt b/tests/requirements.txt
index 1f9ef4e..b7f098b 100644
--- a/tests/requirements.txt
+++ b/tests/requirements.txt
@@ -1,4 +1,4 @@
-black==19.10b0
+black==20.8b1
 coverage==5.2.1
 flake8==3.8.3
 flake8-quotes==3.2.0