anchor.diff:      // Pressing either the Apply or Cancel button will dismiss.
       showDialog(
         context: context,
  -      builder: (BuildContext context) => SnapshotFilterDialog(controller),
  +      builder: (BuildContext context) => SnapshotFilterDialog(_controller),
         barrierDismissible: false,
       );
     }
  
positive.code:   matchingCriteria.forEach((key, value) {
      if (value.isNotEmpty) {
        final name = value;
        String regEx;
        // TODO(terry): Need to handle $ for identifier names e.g.,
        //              $FOO is a valid identifier.
        switch (key) {
  
negative.code:     // Debug only check.
      assert(() {
        // Analysis already completed we're done.
        final foundMatch = _controller.completedAnalyses.firstWhereOrNull(
          (element) => element.dateTime.compareTo(currentSnapDateTime) == 0,
        );
        if (foundMatch != null) {
          logger.log(
  