anchor.diff:    CompletionResult(
         this.replacementOffset, this.replacementLength, this.suggestions);
   }
  +
  +class _RequestToPlugins {
  +  final DartCompletionRequest completionRequest;
  +  final plugin.CompletionGetSuggestionsParams parameters;
  +  final Map<PluginInfo, Future<plugin.Response>> futures;
  +
  +  _RequestToPlugins({
  +    required this.completionRequest,
  +    required this.parameters,
  +    required this.futures,
  +  });
  +}
  
positive.code:         perf.run(SEND_NOTIFICATION_TAG, (_) {
            sendCompletionNotification(
              completionId,
              result.replacementOffset,
              result.replacementLength,
              result.suggestions,
              libraryFile,
              includedSuggestionSets,
              includedElementKinds?.toList(),
  
negative.code: 
        // Compute suggestions in the background
        try {
          var suggestions = await computeSuggestions(
            perf,
            completionRequest,
            includedElementKinds,
            includedElementNames,
            includedSuggestionRelevanceTags,
  