rem: DNDUtils.invokeSession(aEvent.target, ["OutlinerBuilder/column-add"], [column]); 
add: DNDUtils.invokeSession(aEvent.target, ["TreeBuilder/column-add"], [column]); 
context:   onDragGesture: function(aEvent)  {    var box = this.getBoxTarget(aEvent.target);    this.setDraggingBox(box);    if (!box) return false;        var column = this.getColumnValue(box);    if (!column) return false;        DNDUtils.invokeSession(aEvent.target, ["OutlinerBuilder/column-add"], [column]);        return false;  },
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/d38a0937d9c93a0a9d913e2ac781e4328bb8cc73/columnsDialog.js/buggy/extensions/inspector/resources/content/viewers/dom/columnsDialog.js