anchor.diff:  
     final Map<String, int> popularNameCounters = {};
   
  -  final Map<LibraryEntity, String> libraryLongNames = HashMap();
  -
  -  final Map<ConstantValue, jsAst.Name> _constantNames = HashMap();
  +  final Map<LibraryEntity, String> libraryLongNames = {};
  +
  +  final Map<ConstantValue, jsAst.Name> _constantNames = {};
     final Map<ConstantValue, String> _constantLongNames = {};
     ConstantCanonicalHasher _constantHasher;
   
  
positive.code:   /// [_disambiguateMember], [_disambiguateInternalMember],
    /// [_disambiguateOperator], and [reservePublicMemberName].
    final NamingScope instanceScope = NamingScope();
    final Map<String, jsAst.Name> userInstanceMembers = HashMap();
    final Map<String, String> userInstanceMembersOriginalName = HashMap();
    final Map<MemberEntity, jsAst.Name> internalInstanceMembers = HashMap();
    final Map<String, jsAst.Name> userInstanceOperators = HashMap();
    final Map<jsAst.Name, jsAst.Name> userGetters = HashMap();
    final Map<jsAst.Name, jsAst.Name> userSetters = HashMap();
    final Map<TypeVariableEntity, jsAst.Name> _typeVariableNames = {};
  
    Map<String, String> createMinifiedInstanceNameMap() {
  
negative.code:   // parts with the fast-startup emitter.
    String get typesOffsetName => r'typesOffset';
  
    Map<FunctionType, jsAst.Name> functionTypeNameMap = {};
  
    FunctionTypeNamer _functionTypeNamer;
  
  