anchor.diff:    factory TaskResult.fromJson(Map<String, dynamic> json) {
       final bool success = json['success'] as bool;
       if (success) {
  -      final List<String> benchmarkScoreKeys = (json['benchmarkScoreKeys'] as List<dynamic> ?? <String>[]).cast<String>();
  -      final List<String> detailFiles = (json['detailFiles'] as List<dynamic> ?? <String>[]).cast<String>();
  +      final List<String> benchmarkScoreKeys = (json['benchmarkScoreKeys'] as List<dynamic>? ?? <String>[]).cast<String>();
  +      final List<String> detailFiles = (json['detailFiles'] as List<dynamic>? ?? <String>[]).cast<String>();
         return TaskResult.success(json['data'] as Map<String, dynamic>,
           benchmarkScoreKeys: benchmarkScoreKeys,
           detailFiles: detailFiles,
  
positive.code:       : succeeded = true {
      const JsonEncoder prettyJson = JsonEncoder.withIndent('  ');
      if (benchmarkScoreKeys != null) {
        for (final String key in benchmarkScoreKeys) {
          if (!data.containsKey(key)) {
            throw 'Invalid benchmark score key "$key". It does not exist in task '
                'result data ${prettyJson.convert(data)}';
          } else if (data[key] is! num) {
            throw 'Invalid benchmark score for key "$key". It is expected to be a num '
                'but was ${(data[key] as Object).runtimeType}: ${prettyJson.convert(data[key])}';
          }
        }
      }
  
negative.code: // Copyright 2014 The Flutter Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  import 'dart:convert';
  import 'dart:io';
  