private void NotifyUpdate()
        {
            if (_notifyUpdateDelegate == null)
            {
                return;
            }
            EngineRuleCollection collection = GetEmptyRuleCollection();

            foreach (EngineRule rule in _listRules.Items)
            {
                if (rule != _defaultRule)
                {
                    collection.SetRule(rule.Identifier, rule.VirtualizationType);
                }
            }
            _notifyUpdateDelegate(collection);
        }