A couple of tweaks.

pkg/analyzer/lib/src/dart/element/element.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.dart.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 1895 matching lines @@
       EnumElementImpl typeImpl = type;
       if (typeImpl.identifier == identifier) {
         return typeImpl;
       }
     }
     return null;
   }
 
   @override
   ClassElement getEnum(String enumName) {
-    for (ClassElement enumDeclaration in _enums) {
+    for (ClassElement enumDeclaration in enums) {
       if (enumDeclaration.name == enumName) {
         return enumDeclaration;
       }
     }
     return null;
   }
 
   @override
   ClassElement getType(String className) {
     for (ClassElement type in types) {
@@ skipping 7993 matching lines @@
 
   @override
   DartObject computeConstantValue() => null;
 
   @override
   void visitChildren(ElementVisitor visitor) {
     super.visitChildren(visitor);
     _initializer?.accept(visitor);
   }
 }