getDefaultContent example

    public function asEmailMessage(EmailRecipientInterface $recipient, string $transport = null): ?EmailMessage
    {
        if (!class_exists(NotificationEmail::class)) {
            throw new \LogicException(sprintf('The "%s" method requires "symfony/twig-bridge:>4.4".', __METHOD__));
        }

        $email = NotificationEmail::asPublicEmail()
            ->to($recipient->getEmail())
            ->subject($this->getSubject())
            ->content($this->getContent() ?: $this->getDefaultContent('button below'))
            ->action('Sign in', $this->loginLinkDetails->getUrl())
        ;

        return new EmailMessage($email);
    }

    public function asSmsMessage(SmsRecipientInterface $recipient, string $transport = null): ?SmsMessage
    {
        return new SmsMessage($recipient->getPhone(), $this->getDefaultContent('link').' '.$this->loginLinkDetails->getUrl());
    }