fix hints from analyzer in analyzer

pkg/analyzer/test/generated/all_the_rest_test.dart

Index: pkg/analyzer/test/generated/all_the_rest_test.dart
diff --git a/pkg/analyzer/test/generated/all_the_rest_test.dart b/pkg/analyzer/test/generated/all_the_rest_test.dart
index 6f3aa5dbbf11eff9dc971b1eb06ebdd86e27336a..bb6c95a4a4949f4090a4867cbb91cf6f27863232 100644
--- a/pkg/analyzer/test/generated/all_the_rest_test.dart
+++ b/pkg/analyzer/test/generated/all_the_rest_test.dart
@@ -6356,7 +6356,8 @@ class ElementBuilderTest extends EngineTestCase {
 
   void _assertHasDocRange(
       Element element, int expectedOffset, int expectedLength) {
-    SourceRange docRange = element.docRange;
+    // Cast to dynamic here to avoid a hint about @deprecated docRange.
+    SourceRange docRange = (element as dynamic).docRange;
     expect(docRange, isNotNull);
     expect(docRange.offset, expectedOffset);
     expect(docRange.length, expectedLength);