diff --git a/neutron/tests/base.py b/neutron/tests/base.py
index e34dcc38b7..adda2a0bd8 100644
--- a/neutron/tests/base.py
+++ b/neutron/tests/base.py
@@ -194,3 +194,23 @@ class BaseTestCase(testtools.TestCase):
             elif isinstance(value, dict):
                 dic[key] = self.sort_dict_lists(value)
         return dic
+
+    def assertDictSupersetOf(self, expected_subset, actual_superset):
+        """Checks that actual dict contains the expected dict.
+
+        After checking that the arguments are of the right type, this checks
+        that each item in expected_subset is in, and matches, what is in
+        actual_superset. Separate tests are done, so that detailed info can
+        be reported upon failure.
+        """
+        if not isinstance(expected_subset, dict):
+            self.fail("expected_subset (%s) is not an instance of dict" %
+                      type(expected_subset))
+        if not isinstance(actual_superset, dict):
+            self.fail("actual_superset (%s) is not an instance of dict" %
+                      type(actual_superset))
+        for k, v in expected_subset.items():
+            self.assertIn(k, actual_superset)
+            self.assertEqual(v, actual_superset[k],
+                             "Key %(key)s expected: %(exp)r, actual %(act)r" %
+                             {'key': k, 'exp': v, 'act': actual_superset[k]})