refactor(ui_component): update example (#92)

packages/wyatt_ui_components/example/lib/components/custom_app_bar.dart

@@ -10,7 +10,7 @@ class CustomAppBar extends AppBarComponent {
       );
 
   @override
-  AppBarComponent configure(
+  AppBarComponent? configure(
           {String? title, Widget? leading, List<Widget>? actions}) =>
       CustomAppBar(
         title: title ?? this.title,

packages/wyatt_ui_components/example/lib/components/custom_bottom_bar.dart

@@ -29,7 +29,7 @@ class CustomBottomNavigationBar extends BottomNavigationBarComponent {
       );
 
   @override
-  CustomBottomNavigationBar configure({
+  CustomBottomNavigationBar? configure({
     void Function(BuildContext, int)? onTap,
     int currentIndex = 0,
   }) =>

packages/wyatt_ui_components/example/lib/components/custom_error_widget.dart

@@ -11,6 +11,6 @@ class CustomErrorWidget extends ErrorWidgetComponent {
       );
 
   @override
-  ErrorWidgetComponent configure({String? error}) =>
+  ErrorWidgetComponent? configure({String? error}) =>
       CustomErrorWidget(error: error ?? this.error);
 }

packages/wyatt_ui_components/example/lib/components/custom_loading_widget.dart

@@ -12,7 +12,7 @@ class CustomLoadingWidget extends LoadingWidgetComponent {
       );
 
   @override
-  CustomLoadingWidget configure({Color? color}) => CustomLoadingWidget(
+  CustomLoadingWidget? configure({Color? color}) => CustomLoadingWidget(
         color: color ?? this.color,
       );
 }