public static function instance($user, ?\context $context = null) {

        $userid = $user;
        if (!is_scalar($userid)) {
            $userid = $user->id;
        }

        if (self::$cachedid === $userid) {
            return self::$cachedinstance;
        }

        $cachedinstance = new \core_analytics\user($user, $context);
        self::$cachedinstance = $cachedinstance;
        self::$cachedid = (int)$userid;
        return self::$cachedinstance;
    }