* Checks if a permission string is a user permission.
     *
     * @param permission The permission string.
     * @return true if it is a user permission, false otherwise.
     */
    public boolean isUserPermission(final String permission) {
        if (StringUtil.isNotBlank(permission)) {
            return permission.startsWith(ComponentUtil.getFessConfig().getRoleSearchUserPrefix());
        }
        return false;
    }

            return true;
        }

        final SystemHelper systemHelper = ComponentUtil.getSystemHelper();
        for (final String permission : ldapUser.getPermissions()) {
            if (!systemHelper.isUserPermission(permission)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Creates a new LDAP user instance with the specified username and environment.