diff --git a/nova/test.py b/nova/test.py
index 529cce5cb..8ef301682 100644
--- a/nova/test.py
+++ b/nova/test.py
@@ -454,3 +454,42 @@ class MatchType(object):
 
     def __repr__(self):
         return "<MatchType:" + str(self.wanttype) + ">"
+
+
+class ContainKeyValue(object):
+    """Checks whether a key/value pair is in a dict parameter.
+
+    The ContainKeyValue class is a helper for use with the
+    mock.assert_*() method that lets you assert that a particular
+    dict contain a key/value paire. It enables strict check than
+    the built in mock.ANY helper, and is the equivalent of the
+    mox.ContainsKeyValue() function from the legacy mox library
+
+    Example usage could be:
+
+      mock_some_method.assert_called_once_with(
+            "hello",
+            ContainKeyValue('foo', bar),
+            mock.ANY,
+            "world",
+            ContainKeyValue('hello', world))
+    """
+    def __init__(self, wantkey, wantvalue):
+        self.wantkey = wantkey
+        self.wantvalue = wantvalue
+
+    def __eq__(self, other):
+        try:
+            return other[self.wantkey] == self.wantvalue
+        except (KeyError, TypeError):
+            return False
+
+    def __ne__(self, other):
+        try:
+            return other[self.wantkey] != self.wantvalue
+        except (KeyError, TypeError):
+            return True
+
+    def __repr__(self):
+        return "<ContainKeyValue: key " + str(self.wantkey) + \
+               " and value " + str(self.wantvalue) + ">"