Normalize whitespace
diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index 98903bc..6cf112a 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -27,7 +27,7 @@
         if cls is AbstractContextManager:
             if (any("__enter__" in B.__dict__ for B in C.__mro__) and
                 any("__exit__" in B.__dict__ for B in C.__mro__)):
-                    return True
+                return True
         return NotImplemented