public bool AnyChildrenSelected()
 {
     foreach (AssetItem asset in children)
     {
         if (asset is FolderItem)
         {
             FolderItem folder = (FolderItem)asset;
             if (folder.AnyChildrenSelected())
             {
                 return(true);
             }
         }
         else
         {
             if (asset.selected)
             {
                 return(true);
             }
         }
     }
     return(false);
 }