rem: canMoveDown:      function canMoveDown() { return false; }, 
add: optgroupObject.prototype.canMoveDown = function canMoveDown() { return this.treeItem.nextSibling; } 
context:     canMoveDown:      function canMoveDown()    {      return false;    },
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/d38a0937d9c93a0a9d913e2ac781e4328bb8cc73/EdSelectProps.js/buggy/editor/ui/dialogs/content/EdSelectProps.js