anchor.diff:    }
   
     /// Return null if no match, otherwise string.
  -  String matchSearch(Reference ref, String matchString) {
  -    final knownName = ref.name.toLowerCase();
  +  String? matchSearch(Reference ref, String matchString) {
  +    final knownName = ref.name!.toLowerCase();
       if (knownName.contains(matchString.toLowerCase())) {
         return ref.name;
       }
  
positive.code:       classAllocation.instancesDelta = 0;
      }
  
      controller.monitorAllocations = currentAllocations;
    }
  
    /// Match, found,  select it and process via ValueNotifiers.
  
negative.code:     bool takeSnapshot = false;
      final sampleTime = Duration(milliseconds: heapSample.timestamp);
  
      final rssExceeded = heapSum > heapSample.rss;
      if (rssExceeded) {
        final increase = heapSum - lastSnapshotMemoryTotal;
        final rssPercentIncrease = lastSnapshotMemoryTotal > 0
  