Fix minor bugs and remove unnecessary functions

diff --git a/packages/devtools_app/lib/src/inspector/flutter/inspector_screen_details_tab.dart b/packages/devtools_app/lib/src/inspector/flutter/inspector_screen_details_tab.dart
index cc1c35d..d88cd7a 100644
--- a/packages/devtools_app/lib/src/inspector/flutter/inspector_screen_details_tab.dart
+++ b/packages/devtools_app/lib/src/inspector/flutter/inspector_screen_details_tab.dart

@@ -169,7 +169,8 @@
   Widget build(BuildContext context) {
     super.build(context);
     // TODO(albertusangga): Visualize non-flex widget constraint model
-    if (root == null) return const SizedBox();
+    if (root == null || !StoryOfYourFlexWidget.shouldDisplay(selected))
+      return const SizedBox();
     final flexLayoutProperties = FlexLayoutProperties.fromDiagnostics(root);
     final highlightChild =
         selected.isFlex ? null : selected.parent.childrenNow.indexOf(selected);

diff --git a/packages/devtools_app/lib/src/inspector/inspector_service.dart b/packages/devtools_app/lib/src/inspector/inspector_service.dart
index 837ac29..40bcea8 100644
--- a/packages/devtools_app/lib/src/inspector/inspector_service.dart
+++ b/packages/devtools_app/lib/src/inspector/inspector_service.dart

@@ -955,9 +955,10 @@
     ));
   }
 
-  static const getDetailsSubtreeWithRenderObjectServiceExtensionName = 'getDetailsSubtreeWithRenderObject';
-
-  Future<RemoteDiagnosticsNode> getDetailsSubtreeWithRenderObject(RemoteDiagnosticsNode node, { int subtreeDepth = 1 }) async {
+  Future<RemoteDiagnosticsNode> getDetailsSubtreeWithRenderObject(
+    RemoteDiagnosticsNode node, {
+    int subtreeDepth = 1,
+  }) async {
     if (node == null) return null;
     final id = node.dartDiagnosticRef.id;
     String command = '''