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pkg/compiler/lib/src/kernel/kernel_strategy.dart

 // Copyright (c) 2017, 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 dart2js.kernel.frontend_strategy;
 
 import '../closure.dart';
 import '../common.dart';
 import '../common_elements.dart';
 import '../common/backend_api.dart';
@@ skipping 163 matching lines @@
 
 /// Mock implementation of [MirrorsDataImpl].
 class MirrorsDataBuilderImpl extends MirrorsDataImpl {
   MirrorsDataBuilderImpl() : super(null, null, null);
 
   @override
   void registerUsedMember(MemberEntity member) {}
 
   @override
   void computeMembersNeededForReflection(
-      ResolutionWorldBuilder worldBuilder, ClosedWorld closedWorld) {}
+      ResolutionWorldBuilder worldBuilder, ClosedWorld closedWorld) {
+    // TODO(johnniwinther): Support dart:mirrors.
+    createImmutableSets();
+  }
 
   @override
   void maybeMarkClosureAsNeededForReflection(
       ClosureClassElement globalizedElement,
       FunctionElement callFunction,
       FunctionElement function) {}
 
   @override
   void registerConstSymbol(String name) {}
 
@@ skipping 37 matching lines @@
     return new MirrorsCodegenAnalysisImpl();
   }
 
   @override
   void onResolutionComplete() {}
 }
 
 class MirrorsCodegenAnalysisImpl implements MirrorsCodegenAnalysis {
   @override
   int get preMirrorsMethodCount {
-    throw new UnimplementedError(
-        'MirrorsCodegenAnalysisImpl.preMirrorsMethodCount');
+    // TODO(johnniwinther): Implement this.
+    return null;
   }
 
   @override
   void onQueueEmpty(Enqueuer enqueuer, Iterable<ClassEntity> recentClasses) {
-    throw new UnimplementedError('MirrorsCodegenAnalysisImpl.onQueueEmpty');
+    // TODO(johnniwinther): Implement this.
   }
 }