internal void InvalidateParentItems(IEnumerable <uint> itemIds)
        {
            var updates = new Dictionary <Microsoft.VisualStudio.FSharp.ProjectSystem.HierarchyNode, Microsoft.VisualStudio.FSharp.ProjectSystem.HierarchyNode>();

            foreach (var itemId in itemIds)
            {
                var hierarchyNode = FSProjectManager.NodeFromItemId(itemId);
                updates[hierarchyNode.Parent] = hierarchyNode;
            }

            uint lastItemId = VSConstants.VSITEMID_NIL;

            foreach (var item in updates)
            {
                item.Value.OnInvalidateItems(item.Key);
                lastItemId = item.Value.ID;
            }

            if (lastItemId != VSConstants.VSITEMID_NIL)
            {
                GlobalServices.solutionExplorer.ExpandItem(this, lastItemId, EXPANDFLAGS.EXPF_SelectItem);
            }
        }