issue9859: add the missing versionadded tag to the documentation.
diff --git a/Doc/library/test.rst b/Doc/library/test.rst
index 029f930..8f2df7c 100644
--- a/Doc/library/test.rst
+++ b/Doc/library/test.rst
@@ -577,6 +577,8 @@
    By default this skips private attributes beginning with '_' but
    includes all magic methods, i.e. those starting and ending in '__'.
 
+   .. versionadded:: 3.5
+
 
 The :mod:`test.support` module defines the following classes: