code: private void checkNavigationMenuState(final HttpServletRequest req) {
  		if (req == null)
  			return;
  
  		if (req.getSession().getAttribute(ATTR_IS_NAV_MENU_COLLAPSED) != null)
  			return;
  
  		// here we can specify default collapse value
  		req.getSession().setAttribute(ATTR_IS_NAV_MENU_COLLAPSED, false);
  	}
docs: Check, if navigation menu default state present in request. If there is no state, set default value.
  
  @param req
  {@link HttpServletRequest}