Merge 3.3
diff --git a/Doc/library/contextlib.rst b/Doc/library/contextlib.rst
index f18c100..86c3ab0 100644
--- a/Doc/library/contextlib.rst
+++ b/Doc/library/contextlib.rst
@@ -279,7 +279,7 @@
 
          with ExitStack() as stack:
              files = [stack.enter_context(open(fname)) for fname in filenames]
-             close_files = stack.pop_all().close
+             close_files = stack.pop_all().close()
              # If opening any file fails, all previously opened files will be
              # closed automatically. If all files are opened successfully,
              # they will remain open even after the with statement ends.