anchor.diff:  // 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.
  -
  -// @dart = 2.10
   
   import '../common.dart';
   import '../common/elements.dart';
  
positive.code:     Set<InterfaceType> instantiatedTypes = {};
      getInstantiationMap().forEach((_, InstantiationInfo info) {
        if (info.instantiationMap != null) {
          for (Set<Instance> instances in info.instantiationMap.values) {
            for (Instance instance in instances) {
              instantiatedTypes.add(instance.type);
            }
  
negative.code:       ClassEntity cls, MemberEntity member, MemberUsedCallback memberUsed,
        {bool checkEnqueuerConsistency = false}) {
      if (!member.isInstanceMember) return;
      String memberName = member.name!;
  
      MemberUsage? usage = _memberUsage[member];
      if (usage == null) {
        EnumSet<MemberUse> useSet = EnumSet();
        usage = _getMemberUsage(member, useSet,
  