anchor.diff:        String link = _makeLink(COMPLETION_PATH, {
           'index': '$index'
         }, '${performance.startTimeAndMs}');
  -      _writeRow2(
  +      _writeRow(
             buffer,
             [
                 link,
  
positive.code:           request,
            'Query parameter $STATE_QUERY_PARAM is invalid');
      }
  
      // Figure out which context is being searched for.
      String contextFilter = request.uri.queryParameters[CONTEXT_QUERY_PARAM];
      if (contextFilter == null) {
        return _returnFailure(
            request,
            'Query parameter $CONTEXT_QUERY_PARAM required');
      }
  
      // Figure out which descriptor is being searched for.
      String descriptorFilter =
          request.uri.queryParameters[DESCRIPTOR_QUERY_PARAM];
  
negative.code:       if (len > 0) {
          var op = handler.priorityChangedPerformance.operations[len - 1];
          if (op != null) {
            _writeRow(buffer, ['&nbsp;', '&nbsp;', '&nbsp;']);
            String elapsed = op.elapsed != null ? op.elapsed.toString() : '???';
            _writeRow(buffer, [elapsed, '&nbsp;&nbsp;', op.name]);
          }
        }
      }
  