private static IMenuBarSubMenu createGroupingSubMenu(ITreeNode <RootNodeType> treeNode, IExplorerPresenter presenter)
{
var groupMenu = CreateSubMenu.WithCaption(MenuNames.GroupBy);
presenter.AvailableClassificationCategories(treeNode)
.Each(classification => groupMenu.AddItem(
CreateMenuButton.WithCaption(classification.ClassificationName)
.WithActionCommand(() => presenter.AddToClassificationTree(treeNode, classification.ClassificationName))));
return(groupMenu);
}