From 443cc0114d7669471e39661c97e2bad91c8eabb8 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Wed, 28 Sep 2016 11:10:27 +1000
Subject: [PATCH] tests/basics: Add test for set.difference_update with arg
 being itself.

---
 tests/basics/set_difference.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/basics/set_difference.py b/tests/basics/set_difference.py
index abfcbe7d63..97b63a8150 100644
--- a/tests/basics/set_difference.py
+++ b/tests/basics/set_difference.py
@@ -14,3 +14,6 @@ print(s.difference_update({1}))
 print(sorted(s))
 print(s.difference_update({1}, [2]))
 print(sorted(s))
+
+s.difference_update(s)
+print(s)