minor change

lib/widgets/album/grid/list_sliver.dart

@@ -12,6 +12,8 @@ import 'package:provider/provider.dart';
 // with the multiple `SliverGrid` solution, thumbnails at the beginning of each sections are built even though they are offscreen
 // because of `RenderSliverMultiBoxAdaptor.addInitialChild` called by `RenderSliverGrid.performLayout` (line 547), as of Flutter v1.17.0
 class CollectionListSliver extends StatelessWidget {
+  const CollectionListSliver();
+
   @override
   Widget build(BuildContext context) {
     final sectionLayouts = Provider.of<SectionedListLayout>(context).sectionLayouts;

lib/widgets/album/thumbnail_collection.dart

@@ -107,13 +107,13 @@ class _ScalableThumbnailCollection extends StatelessWidget {
       // when there is no content and we use `SliverFillRemaining`
       physics: collection.isEmpty ? const NeverScrollableScrollPhysics() : null,
       slivers: [
-      appBar,
+        appBar,
         collection.isEmpty
             ? SliverFillRemaining(
                 child: _buildEmptyCollectionPlaceholder(collection),
                 hasScrollBody: false,
               )
-            : CollectionListSliver(),
+            : const CollectionListSliver(),
         SliverToBoxAdapter(
           child: Selector<MediaQueryData, double>(
             selector: (context, mq) => mq.viewInsets.bottom,