public override bool CanBeParent(TreeViewItem item)
 {
     if (item is SearchFilterTreeItem)
     {
         return(SavedSearchFilters.AllowsHierarchy());
     }
     return(true);
 }
 public override bool CanBeParent(TreeViewItem item) =>
 (!(item is SearchFilterTreeItem) || SavedSearchFilters.AllowsHierarchy());