anchor.diff:  import 'package:angel_framework/angel_framework.dart';
   import 'package:graphql_schema/graphql_schema.dart';
  +
  +Map<String, dynamic> _fetchRequestInfo(Map<String, dynamic> arguments) {
  +  return <String, dynamic> {
  +    '__requestctx': arguments.remove('__requestctx'),
  +    '__responsectx': arguments.remove('__responsectx'),
  +  };
  +}
   
   /// A GraphQL resolver that `index`es an Angel service.
   ///
  
positive.code:     resolveViaServiceRead<Value, Serialized>(Service service,
          {String idField: 'id'}) {
    return (_, arguments) async {
      var params = {'query': arguments, 'provider': Providers.graphql};
      var id = arguments.remove(idField);
      return await service.read(id, params) as Value;
    };
  
negative.code:     resolveViaServiceModify<Value, Serialized>(Service service,
          {String idField: 'id'}) {
    return (_, arguments) async {
      var _requestInfo = _fetchRequestInfo(arguments);
      var params = {'query': arguments, 'provider': Providers.graphql}..addAll(_requestInfo);
      var id = arguments.remove(idField);
      return await service.modify(id, arguments['data'], params) as Value;
    };
  