use Creonit\SendPulseMailer\Header\SendPulseVariableHeader;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\Mailer\MailerInterface;
use Symfony\Component\Mime\Email;

class MailingController extends AbstractController
{
    public function sendMail(MailerInterface $mailer)
    {
        $to = '[email protected]';
        $message = new Email();
        $message->to($to);
        $message->getHeaders()
            ->addTextHeader('X-SendPulse-Event', 'event_name')
            ->add(new SendPulseVariableHeader('variable_name', 'value'));
        
        $mailer->send($message);
    }
}