anchor.diff:    PaperIconButton _resetButton;
     PaperTabs _tabs;
   
  -  Map _lastRun;
  +  Map<String, String> _lastRun;
     Router _router;
     
  -  CompileResponse _storedResponse;
  +  CompileResponse _cachedCompile;
     Editor editor;
     PlaygroundContext _context;
     Future _analysisRequest;
  
positive.code:     });
    }
  
    bool _requestStored() {
      return (_lastRun != null && _lastRun['dart'] == context.dartSource && _lastRun['html'] == context.htmlSource 
          &&  _lastRun['css'] == context.cssSource && _storedResponse != null);
    }
   
    void _backupRun() {
      var input = new CompileRequest()..source = context.dartSource;
      _setBackup();
      dartServices
          .compile(input)
          .timeout(longServiceCallTimeout)
          .then((CompileResponse response) {
        _storedResponse = response;
      });
    }
    
  
negative.code:     }
  
      _showGist(gistId, run: page == 'run');
      _storePreviousResult();
    }
  
    void registerMessageToast() {
  