anchor.diff:  ArgParser argParser = new ArgParser()
     ..addOption('stacks',
         abbr: 's',
  -      defaultsTo: '30',
  -      help: 'Number of highest ranking stacks to print.')
  +      defaultsTo: '0',
  +      help: 'Number of highest ranking stacks to print (0 for all).')
     ..addOption('length',
         abbr: 'l', defaultsTo: '12', help: 'Number of stack frames printed.');
   
  
positive.code: }
  
  trieLeaves(node) sync* {
    if (node.map.isEmpty) {
      yield node;
    } else {
      for (var v in node.map.values) {
        yield* trieLeaves(v);
      }
    }
  }
  
negative.code:       print('  $line');
      }
    }
  }
  
  String fullReasonOf(Record r) {
    // Some records have no matched reason, so default to test status.
    return r.fullReason ?? r.actual;
  }
  
  int compareNodesByCountAndStack(TrieNode a, TrieNode b) {
  