anchor.diff:        counter.increment("Completions");
         var response = await analysisServer.completeMulti(sources,
           new Location()
  -          ..sourceName = name
  +          ..sourceName = sourceName
             ..offset = offset);
         _logger.info('PERF: Computed completions in ${watch.elapsedMilliseconds}ms.');
         return response;
  
positive.code:     counter.increment("Fixes");
      var response = await analysisServer.getFixesMulti(sources,
        new Location()
          ..sourceName = name
          ..offset = offset);
      _logger.info('PERF: Computed fixes in ${watch.elapsedMilliseconds}ms.');
      return response;
  
negative.code:   }
  
    Future<FixesResponse> _fixesMulti(Map<String, String> sources,
      String sourceName, int offset) async {
      if (sources == null) {
        throw new BadRequestError('Missing parameter: \'sources\'');
      }
  