fix test_unittest: ignore DeprecationWarning on assertDictContainsSubset()

Lib/unittest/test/test_assertions.py

 import datetime
-
+import warnings
 import unittest
 
 
@@ -224,6 +224,9 @@ class TestLongMessage(unittest.TestCase):
                              "\+ \{'key': 'value'\} : oops$"])
 
     def testAssertDictContainsSubset(self):
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+
             self.assertMessages('assertDictContainsSubset', ({'key': 'value'}, {}),
                                 ["^Missing: 'key'$", "^oops$",
                                  "^Missing: 'key'$",

Lib/unittest/test/test_case.py

@@ -489,6 +489,9 @@ class Test_TestCase(unittest.TestCase, TestEquality, TestHashing):
                           animals)
 
     def testAssertDictContainsSubset(self):
+        with warnings.catch_warnings():
+            warnings.simplefilter("ignore", DeprecationWarning)
+
             self.assertDictContainsSubset({}, {})
             self.assertDictContainsSubset({}, {'a': 1})
             self.assertDictContainsSubset({'a': 1}, {'a': 1})