anchor.diff:      } else {
         spark.navigationManager.goBack();
       }
  +    spark.editorArea.selectedTab.focus();
     }
   }
   
  
positive.code:     _init(true);
    }
  
    void _init(bool value) {
      _forward = value;
      enabled = false;
  
      spark.navigationManager.onNavigate.listen((_) {
  
negative.code: 
      // Ctrl-1 to Ctrl-8. The user types in a 1-based key event; we convert that
      // into a 0-based into into the tabs.
      spark.editorArea.focusTab(spark.editorArea.tabs[_binding.index - 1]);
    }
  }
  
  