private static bool calledWithBaseObjectAndChangeSet(ArgumentCollection args, FlatPropertyBag baseObject, TimestampedPropertyVersionDelta versionDelta)
 {
     var correct = args.Get<IVersionControlNode>(ExistingControllerArgumentName).Mutations.Single().Equals(versionDelta);
     correct &= args.Get<FlatPropertyBag>(ExistingObjectArgumentName).Equals(baseObject);
     return correct;
 }