anchor.diff:    factory _LocalContext.forProperty(
       QueryContext context,
       DeclarationId declarationId,
  -    Option<hir.CandyType> returnType,
  +    Option<hir.CandyType> expressionType,
     ) {
  -    return _LocalContext._(context, declarationId, returnType);
  +    return _LocalContext._(
  +        context, declarationId, expressionType, Option.none());
     }
   
     final QueryContext queryContext;
  
positive.code: 
    final Map<String, hir.Identifier> localIdentifiers;
  
    final Option<hir.CandyType> returnType;
    bool isValidReturnType(hir.CandyType type) {
      if (returnType.isNone) return true;
  
negative.code: import 'dart:io';
  
  import 'package:compiler/compiler.dart';
  import 'package:dartx/dartx.dart';
  import 'package:parser/parser.dart' as ast;
  