final ListStore<GWTJahiaNode> store = new ListStore<GWTJahiaNode>(loader);
childrenGrid = new Grid<GWTJahiaNode>(store, new ColumnModel(columnConfigList));
childrenGrid.setBorders(true);
childrenGrid.setHeight(400);
new GridDragSource(childrenGrid);
GridDropTarget target = new GridDropTarget(childrenGrid);
target.setAllowSelfAsSource(true);
target.setFeedback(DND.Feedback.INSERT);