anchor.diff:      return question;
     }
   
  -  static Rti _getFutureFromFutureOr(universe, Rti rti) {
  +  static Rti _getFutureFromFutureOr(Object? universe, Rti rti) {
       assert(_getKind(rti) == kindFutureOr);
  -    Rti? future = _castToRtiOrNull(_getPrecomputed1(rti));
  +    Rti? future = _Utils.asRtiOrNull(_getPrecomputed1(rti));
       if (future == null) {
         future = _Universe._lookupFutureRti(universe, _getFutureOrArgument(rti));
         Rti._setPrecomputed1(rti, future);
  
positive.code: 
  /// Returns the structural function type of [object], or `null` if the object is
  /// not a closure.
  Rti? _instanceFunctionType(object) =>
      _isClosure(object) ? closureFunctionType(object) : null;
  
  /// Returns Rti from types table. The types table is initialized with recipe
  /// strings.
  Rti getTypeFromTypesTable(/*int*/ _index) {
    int index = _Utils.asInt(_index);
    var table = JS_EMBEDDED_GLOBAL('', TYPES);
    var type = _Utils.arrayAt(table, index);
    if (_Utils.isString(type)) {
  
negative.code: }
  
  @pragma('dart2js:noInline') // Slightly smaller code.
  bool _finishIsFn(Rti testRti, Object? object, Object? isFn) {
    Rti._setIsTestFunction(testRti, isFn);
    return Rti._isCheck(testRti, object);
  }
  