collections.chainmap: test_chainmap: Add test for .items().

Signed-off-by: Paul Sokolovsky <pfalcon@users.sourceforge.net>

Author: pfalcon

collections.chainmap/test_chainmap.py

@@ -6,6 +6,9 @@
 assert cm["k2"] == "v2"
 assert cm["k3"] == "v3"
 
+items = sorted(list(cm.items()))
+assert items == [('k1', 'v11'), ('k2', 'v2'), ('k3', 'v3')]
+
 del cm["k1"]
 assert cm["k1"] == "v12"
 cm["k1"] = "newv"