just forget it, back to roots but better

Pilz.UI.Telerik/Dialogs/RadFlyoutBase.Statics.cs

@@ -102,20 +102,12 @@ partial class RadFlyoutBase
         titleToAssing = title;
         iconToAssign = icon;
         ParentContext = controlToAssociate;
-        CloseFlyout(false); // Ensure it's closed!
+        CloseFlyout(); // Ensure it's closed!
         RadFlyoutManager.Show(controlToAssociate, flyoutContentType);
     }
 
     protected static void CloseFlyout()
     {
-        CloseFlyout(true);
-    }
-
-    protected static void CloseFlyout(bool throwOnError)
-    {
-        if (throwOnError && ParentContext is null)
-            throw new NullReferenceException(nameof(ParentContext));
-
         if (typeof(RadFlyoutManager).GetField("flyoutInstance", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static).GetValue(null) is FlyoutScreen instance
             && instance.IsActive)
             RadFlyoutManager.Close();