* @return \Illuminate\Contracts\Auth\Authenticatable
     *
     * @throws \Illuminate\Auth\AuthenticationException
     */
    public function authenticate()
    {
        if (! is_null($user = $this->user())) {
            return $user;
        }

        throw new AuthenticationException;
    }

    /**
     * Determine if the current user is authenticated.
     *
     * @return bool
     */
    public function check()
    {
        return ! is_null($this->user());
    }

    /**
     * Determine if the current user is a guest.
     *
     * @return bool
     */
    public function guest()
    {
        return ! $this->check();
Arguments
"Unauthenticated."