public function issue(array $customClaims = [])
    {
        // ensure there is a user logged in.
        if (!$this->user) {
            return false;
        }

        // try to issue a new token and return.
        try {
            return $this->manager()->issue($this->user, $customClaims);
        } catch (\Exception $e) {
            // catch any exceptions that the token issuing may trigger.
            return false;
        }
    }