anchor.diff:  
   bool isFutureOrType(Rti t) => Rti._getKind(t) == Rti.kindFutureOr;
   
  +bool isEitherFunctionKind(Rti t) =>
  +    isFunctionKind(t) || isGenericFunctionKind(t);
  +bool isFunctionKind(Rti t) => Rti._getKind(t) == Rti.kindFunction;
   bool isGenericFunctionKind(Rti t) => Rti._getKind(t) == Rti.kindGenericFunction;
   
   bool isGenericFunctionTypeParameter(Rti t) =>
  
positive.code: }
  
  Type getRuntimeType(object) {
    Rti rti = _instanceFunctionType(object) ?? instanceType(object);
    return _createRuntimeType(rti);
  }
  
  
negative.code:   static const kindGenericFunction = 11;
    static const kindGenericFunctionParameter = 12;
  
    static bool _isUnionOfFunctionType(Rti rti) {
      int kind = Rti._getKind(rti);
      if (kind == kindStar || kind == kindQuestion || kind == kindFutureOr) {
        return _isUnionOfFunctionType(_castToRti(_getPrimary(rti)));
      }
      return kind == kindFunction || kind == kindGenericFunction;
    }
  
  