Fixed typo with asynccontextmanager code example (GH-8845)

alvassin · Mariatta · commit 416cbce22d5d · 2018-08-24T19:38:11.000-07:00
`yield conn`, instead of just `yield`.
diff --git a/Doc/library/contextlib.rst b/Doc/library/contextlib.rst
@@ -116,7 +116,7 @@ Functions and classes provided:
       async def get_connection():
           conn = await acquire_db_connection()
           try:
-              yield
+              yield conn
           finally:
               await release_db_connection(conn)
 
