anchor.diff:            ..write(');');
         }
   
  -      _buffer.write('''\n    return val;
  +      buffer.write('''\n    return val;
     }''');
   
         final fieldKeyMap = Map.fromEntries(data.usedCtorParamsAndFields
  
positive.code:       args.add('disallowNullValues: $disallowNullKeyLiteral');
      }
  
      if (args.isNotEmpty) {
        _buffer.writeln('${' ' * indent}\$checkKeys(json, ${args.join(', ')});');
      }
    }
  
    String _deserializeForField(FieldElement field,
        {ParameterElement ctorParam, bool checkedProperty}) {
      checkedProperty ??= false;
      final jsonKeyName = safeNameAccess(field);
      final targetType = ctorParam?.type ?? field.type;
  
negative.code: 
  import 'package:analyzer/dart/element/element.dart';
  import 'package:build/build.dart';
  import 'package:source_gen/source_gen.dart';
  
  import 'helper_core.dart';
  