rem: isCommandEnabled: function (aCommand) 
add: isCommandEnabled: function(aCommand) 
context:   isCommandEnabled: function (aCommand)  {    if (!window.gDownloadsView)      return false;        switch (aCommand) {    case "cmd_cleanUp":      return gDownloadManager.canCleanUp;    case "cmd_remove":      return gDownloadsView.selectedItem != null;    }    return false;  },
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/8395/43455f9fc69a7b8e33dae13cc90fd333fc5448d2/downloads.js/buggy/toolkit/mozapps/downloads/content/downloads.js