asset image not support

Samples/UIWidgetsSamples_2019_4/Assets/UIWidgetsGallery/demo/cupertino/cupertino_navigation_demo.cs

         public readonly List<string> colorNameItems;
 
         public override Widget build(BuildContext context) {
+            
             return new WillPopScope(
                 //onWillPop: () => { return Promise<bool>.Resolved(true); },
                 //onWillPop: this.onWillPop,
                                     title: new Text("Profile")
                                 )
                             }
+                            
                         ),
                         tabBuilder: (BuildContext _context, int index) => {
                             D.assert(index >= 0 && index <= 2);
                                                         height: 44.0f,
                                                         decoration: new BoxDecoration(
                                                             image: new DecorationImage(
-                                                                image: new AssetImage(
-                                                                    "people/square/trevor"
+                                                                image: new FileImage(
+                                                                    file:""
                                                                 )
                                                             ),
                                                             shape: BoxShape.circle
                                                         height: 44.0f,
                                                         decoration: new BoxDecoration(
                                                             image: new DecorationImage(
-                                                                image: new AssetImage(
+                                                                image: new FileImage(
                                                                     "people/square/sandra"
                                                                 )
                                                             ),
                     child: new DecoratedBox(
                         decoration: new BoxDecoration(
                             color: CupertinoTheme.of(context).brightness == Brightness.light
-                                ? CupertinoColors.extraLightBackgroundGray
-                                : CupertinoColors.darkBackgroundGray
+                                ? CupertinoColors.activeOrange
+                                : CupertinoColors.activeGreen
                         ),
                         child: new ListView(
                             children: new List<Widget> {

com.unity.uiwidgets/Runtime/animation/listener_helpers.mixin.gen.cs

                 D.assert(() => {
                       IEnumerable<DiagnosticsNode> infoCollector() {
                           yield return new DiagnosticsProperty<AnimationLocalListenersMixinAnimationEagerListenerMixinAnimation<T>>(
-                              "The " + GetType() + " notifying listeners was",
+                              "The " + GetType() + " notifying listeners was:",
                               this,
                               style: DiagnosticsTreeStyle.errorProperty
                           );

com.unity.uiwidgets/Runtime/rendering/list_wheel_viewport.cs

 using System;
 using System.Collections.Generic;
 using Unity.UIWidgets.animation;
+using Unity.UIWidgets.cupertino;
 using Unity.UIWidgets.foundation;
 using Unity.UIWidgets.gestures;
 using Unity.UIWidgets.painting;
             RenderBox after = null
         ) {
             invokeLayoutCallback<BoxConstraints>((BoxConstraints constraints) => {
-                D.assert(this.constraints == this.constraints);
+                D.assert(constraints == this.constraints);
                 childManager.createChild(index, after: after);
             });
         }
-                D.assert(this.constraints == this.constraints);
+                D.assert(constraints == this.constraints);
                 childManager.removeChild(child);
             });
         }