anchor.diff:        return result;
       }
       return runCommand(['nodejs', js], env);
  +  }
  +
  +  void printReproductionCommand() {
  +    print([dart2js, fileName, '-o', js].join(" "));
  +    print(['nodejs', js].join(" "));
     }
   
     String description;
  
positive.code:     if (mode.endsWith('dbc64')) return 'ReleaseSIMDBC64';
      throw ('unknown tag in mode: $mode');
    }
  }
  
  /// Concrete test runner of Dart JIT.
  
negative.code:       return result;
      }
      return runCommand([dart, snapshot], env);
    }
  
    void printReproductionCommand() {
      print(
          ["DART_CONFIGURATION=${env['DART_CONFIGURATION']}", ...cmd].join(" "));
      print([dart, snapshot].join(" "));
    }
  
    String description;
  