Update components/Extensions/src/ListViewBase/ListViewExtensions.StretchItemContainer.cs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: Arlodotexe

components/Extensions/src/ListViewBase/ListViewExtensions.StretchItemContainer.cs

@@ -20,7 +20,7 @@ public static partial class ListViewExtensions
     /// <param name="obj">The <see cref="ListViewBase"/> to get the associated <see cref="ItemContainerStretchDirection"/> from</param>
     /// <returns>The <see cref="ItemContainerStretchDirection"/> associated with the <see cref="ListViewBase"/></returns>
     public static ItemContainerStretchDirection? GetItemContainerStretchDirection(ListViewBase obj)
-        => (ItemContainerStretchDirection)obj.GetValue(ItemContainerStretchDirectionProperty);
+        => (ItemContainerStretchDirection?)obj.GetValue(ItemContainerStretchDirectionProperty);
 
     /// <summary>
     /// Sets the stretch <see cref="ItemContainerStretchDirection"/> associated with the specified <see cref="ListViewBase"/>