[dartdoc] Updating dart reference docs
diff --git a/sdk/dart/package-fuchsia_inspect_inspect/Inspect/Inspect.forTesting.md b/sdk/dart/package-fuchsia_inspect_inspect/Inspect/Inspect.forTesting.md
index d5d5a0f..cb722ec 100644
--- a/sdk/dart/package-fuchsia_inspect_inspect/Inspect/Inspect.forTesting.md
+++ b/sdk/dart/package-fuchsia_inspect_inspect/Inspect/Inspect.forTesting.md
@@ -23,6 +23,8 @@
 
 ```dart
 factory Inspect.forTesting(FakeVmoHolder vmo) {
+  // Legacy dart analyzer might warn about this.
+  // ignore: unnecessary_cast
   return InspectImpl(VmoWriter.withVmo(vmo as VmoHolder));
 }
 ```