rand dart fix

deprecated/responsive_scaffold/example/lib/examples/layout.dart

@@ -74,7 +74,7 @@ class LayoutExample extends StatelessWidget {
       ),
       floatingActionButton: FloatingActionButton(
         child: Icon(Icons.add),
-        backgroundColor: Theme.of(context).accentColor,
+        backgroundColor: Theme.of(context).colorScheme.secondary,
         onPressed: () {},
       ),
     );

deprecated/responsive_scaffold/example/lib/examples/list.dart

@@ -53,7 +53,7 @@ class _ListExampleState extends State<ListExample> {
           title: Text("App Bar"),
         ),
       ],
-      itemCount: _items?.length ?? 0,
+      itemCount: _items.length ?? 0,
       itemBuilder: (BuildContext context, int index) {
         final i = _items[index];
         return ListTile(