Temp: Skip test_collections.TestChainMap.test_union_operators

Author: xiaozhiyan

Lib/test/test_collections.py

@@ -259,6 +259,8 @@ def __contains__(self, key):
         d = c.new_child(b=20, c=30)
         self.assertEqual(d.maps, [{'b': 20, 'c': 30}, {'a': 1, 'b': 2}])
 
+    # TODO: RUSTPYTHON
+    @unittest.expectedFailure
     def test_union_operators(self):
         cm1 = ChainMap(dict(a=1, b=2), dict(c=3, d=4))
         cm2 = ChainMap(dict(a=10, e=5), dict(b=20, d=4))