anchor.diff:                targetType, expression, _notSupportedWithTypeHelpersMsg));
   }
   
  +String _prefix(ClassElement classElement) => '_\$${classElement.name}';
  +
   String _safeNameAccess(FieldElement field) {
     var name = _jsonKeyFor(field).name ?? field.name;
     // TODO(kevmoo): JsonKey.name could also have quotes and other silly.
  
positive.code:     });
  
      if (classAnnotation.createToJson) {
        var prefix = '_\$${classElement.name}';
        var mixClassName = '${prefix}SerializerMixin';
        var helpClassName = '${prefix}JsonMapWrapper';
  
  
negative.code:     });
  
      if (classAnnotation.createFactory) {
        buffer.writeln();
        buffer.writeln('${classElement.name} '
            '${_prefix(classElement)}FromJson(Map<String, dynamic> json) =>');
  
        String deserializeFun(String paramOrFieldName,
                {ParameterElement ctorParam}) =>
  