Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
        if(authentication == null) {
            throw new IllegalStateException("authentication cannot be null. Make sure you are logged in.");
        }
        Object principal = userDetailsService.loadUserByUsername(authentication.getName());
        model.addAttribute("user", principal);
        model.addAttribute("isLdapUserDetails", principal instanceof LdapUserDetails);
        model.addAttribute("isLdapPerson", principal instanceof Person);
        model.addAttribute("isLdapInetOrgPerson", principal instanceof InetOrgPerson);