void HandleSingleMenu(IContent first)
        {
            var mod = first as IMod;

            if (mod != null)
            {
                _modContextMenu.ShowForItem(mod);
                ContextMenu = _modContextMenu;
                _modBarMenu.ShowForItem(mod);
                BarMenu = _modBarMenu;
            }
            else
            {
                var collection = first as Collection;
                if (collection != null)
                {
                    _collectionContextMenu.ShowForItem(collection);
                    _collectionBarMenu.ShowForItem(collection);
                }
                ContextMenu = _collectionContextMenu;
                BarMenu     = _collectionBarMenu;
            }
        }