// if browser is not IE allow dragging columns headers.
DraggableBehavior draggableBehavior = new DraggableBehavior();
draggableBehavior.setRevert(new DraggableRevert(RevertEnum.INVALID));
draggableBehavior.setContainment(new DraggableContainment("'#"+getTable().getMarkupId() +"_tTH'"));
draggableBehavior.setZIndex(100);
draggableBehavior.setSnap(new DraggableSnap(true));
add(draggableBehavior);
DroppableAjaxBehavior<DraggableTitle<E>> droppableAjaxBehavior = new DroppableAjaxBehavior<DraggableTitle<E>>() {
private static final long serialVersionUID = 1L;