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:       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,
  
negative.code:       final typeArguments = staticUse.typeArguments;
        if (typeArguments != null && typeArguments.isNotEmpty) {
          registerDynamicInvocation(
              Selector.call(Names.call, staticUse.callStructure!), typeArguments);
        }
        return;
      }
  
      MemberEntity element = staticUse.element as MemberEntity;
      EnumSet<MemberUse> useSet = EnumSet();
      MemberUsage usage = _getMemberUsage(element, useSet);
  
      if ((element.isStatic || element.isTopLevel) && element.isField) {
        _allReferencedStaticFields.add(staticUse.element as FieldEntity);
      }
      // TODO(johnniwinther): Avoid this. Currently [FIELD_GET] and
      // [FIELD_SET] contains [BoxFieldElement]s which we cannot enqueue.
  