anchor.diff:    LoadLibraryJudgment(LibraryDependency import) : super(import);
   
     @override
  -  DartType infer<Expression, Statement, Initializer, Type>(
  -      ShadowTypeInferrer inferrer,
  -      Factory<Expression, Statement, Initializer, Type> factory,
  -      DartType typeContext) {
  -    return inferredType =
  +  Expression infer<Expression, Statement, Initializer, Type>(
  +      ShadowTypeInferrer inferrer,
  +      Factory<Expression, Statement, Initializer, Type> factory,
  +      DartType typeContext) {
  +    inferredType =
           inferrer.typeSchemaEnvironment.futureType(const DynamicType());
  +    return null;
     }
   }
   
  
positive.code:   DartType inferredType;
  
    @override
    DartType infer<Expression, Statement, Initializer, Type>(
        ShadowTypeInferrer inferrer,
        Factory<Expression, Statement, Initializer, Type> factory,
        DartType typeContext) {
      inferredType = inferrer.thisType ?? const DynamicType();
      inferrer.listener.thisExpression(this, fileOffset, null, inferredType);
      return inferredType;
    }
  }
  
  
negative.code:             isConst: isConst);
  
    @override
    Expression infer<Expression, Statement, Initializer, Type>(
        ShadowTypeInferrer inferrer,
        Factory<Expression, Statement, Initializer, Type> factory,
        DartType typeContext) {
  