anchor.diff:        symbol = new TraceSymbol(name);
         _symbols[name] = symbol;
       }
  -    // Start at 1 because 0 will always be the isolate.
  -    for (var i = 1; i < _stack.length; i++) {
  -      // Bump inclusive count for all frames.
  -      symbol.inclusive++;
  -    }
       _stack.add(symbol);
  -    if (_stack.length > 1) {
  -      // Only if we aren't the isolate.
  -      symbol.exclusive++;
  -    }
  +    _marked = false;
     }
   
     void _processEnd(Map event) {
  
positive.code:       }
      }
    }
  
  
    static const NUM_SYMBOLS = 10;
  
    void _findTopExclusive() {
      _topExclusive = _symbols.values.toList();
  
negative.code: }
  
  class TraceSummary {
    final int numSymbols;
  
    Map<String, TraceSymbol> _symbols = {};
    List _events = [];
    List<TraceSymbol> _stack = [];
    List<TraceSymbol> _topExclusive = [];
    List<TraceSymbol> _topInclusive = [];
    bool _marked = false;
    int _totalSamples = 0;
  
    TraceSummary(this.numSymbols);
  
    void _processEventsFromFile(String name) {
      var file = new File(name);
  