protected override void OnParametersSet()
 {
     base.OnParametersSet();
     if (StaticList is object)
     {
         things = StaticList
                  .Select(s => new Tag <T>(s, RemoveItem))
                  .ToList();
     }
     else if (StaticDictionary is object)
     {
         things = StaticDictionary
                  .Select(kvp => new Tag <T>(kvp.Value, RemoveItem)
         {
             Label = kvp.Key
         })
                  .ToList();
     }
 }