anchor.diff:    InterfaceType getConstantMapTypeFor(InterfaceType sourceType,
         {bool hasProtoKey: false, bool onlyStringKeys: false});
   
  +  InterfaceType getConstantSetTypeFor(InterfaceType sourceType);
  +
     FieldEntity get symbolField;
   
     InterfaceType get symbolImplementationType;
   
     // From dart:core
     ClassEntity get mapLiteralClass;
  -
     ConstructorEntity get mapLiteralConstructor;
  -
     ConstructorEntity get mapLiteralConstructorEmpty;
  -
     FunctionEntity get mapLiteralUntypedMaker;
  -
     FunctionEntity get mapLiteralUntypedEmptyMaker;
  +
  +  ClassEntity get setLiteralClass;
  +  ConstructorEntity get setLiteralConstructor;
  +  ConstructorEntity get setLiteralConstructorEmpty;
  +  FunctionEntity get setLiteralUntypedMaker;
  +  FunctionEntity get setLiteralUntypedEmptyMaker;
   
     FunctionEntity get objectNoSuchMethod;
   
  
positive.code:   /// If no type argument is provided, the canonical raw type is returned.
    InterfaceType listType([DartType elementType]);
  
    /// Returns an instance of the `Map` type defined in 'dart:core' with
    /// [keyType] and [valueType] as its type arguments.
    ///
  
negative.code:   FunctionEntity get mapLiteralUntypedEmptyMaker {
      _ensureMapLiteralHelpers();
      return _mapLiteralUntypedEmptyMaker;
    }
  
    ClassEntity _setLiteralClass;
    ClassEntity get setLiteralClass => _setLiteralClass ??=
        _findClass(_env.lookupLibrary(Uris.dart_collection), 'LinkedHashSet');
  
    ConstructorEntity _setLiteralConstructor;
    ConstructorEntity _setLiteralConstructorEmpty;
    FunctionEntity _setLiteralUntypedMaker;
    FunctionEntity _setLiteralUntypedEmptyMaker;
  
    void _ensureSetLiteralHelpers() {
      if (_setLiteralConstructor != null) return;
  
      _setLiteralConstructor =
          _env.lookupConstructor(setLiteralClass, '_literal');
      _setLiteralConstructorEmpty =
          _env.lookupConstructor(setLiteralClass, '_empty');
      _setLiteralUntypedMaker =
          _env.lookupLocalClassMember(setLiteralClass, '_makeLiteral');
      _setLiteralUntypedEmptyMaker =
          _env.lookupLocalClassMember(setLiteralClass, '_makeEmpty');
    }
  
    ConstructorEntity get setLiteralConstructor {
      _ensureSetLiteralHelpers();
      return _setLiteralConstructor;
    }
  
    ConstructorEntity get setLiteralConstructorEmpty {
      _ensureSetLiteralHelpers();
      return _setLiteralConstructorEmpty;
    }
  
    FunctionEntity get setLiteralUntypedMaker {
      _ensureSetLiteralHelpers();
      return _setLiteralUntypedMaker;
    }
  
    FunctionEntity get setLiteralUntypedEmptyMaker {
      _ensureSetLiteralHelpers();
      return _setLiteralUntypedEmptyMaker;
    }
  
    FunctionEntity _objectNoSuchMethod;
  