code: public void pop(AbstractDrawer drawer, AjaxRequestTarget target) {
  		Iterator<ListItem> iter = drawers.iterator();
  		while (iter.hasNext()) {
  			ListItem item = iter.next();
  			item.drawer.setAllowClose(true);
  			target.appendJavaScript("$('#"+item.item.getMarkupId()+"').modaldrawer('hide');");
  			if (item.drawer==drawer) {
  				break;
  			}
  		}
  	}
docs: Pops a series of open drawers from the stack and closes them, displaying the one underneath, or the main page.
  This method requires an AJAX request. DrawerManager does not support closing drawers during page construction.
  Note that this code sets each drawer's allow close flag to true. See {@link AbstractDrawer} for more information.
  
  @param drawer
  The last drawer to be closed. This drawer and all the ones above it are closed.
  Open drawers beneath this one are not. If this parameter is null or not in the stack,
  all the drawers are closed.
  @param target
  The current AJAX target. Cannot be null.