onMailBeforeSentEvent example

$flowListener = function DFlowSendMailActionEvent $event) use (&$flowEvent): void {
            $event = $this->onFlowSendMailActionEvent($event);

            if ($event instanceof FlowSendMailActionEvent) {
                $flowEvent = $event;
            }
        };
        $this->addEventListener($this->eventDispatcher, FlowSendMailActionEvent::class, $flowListener);

        $mailEvent = null;
        $mailListener = function DMailBeforeSentEvent $event) use (&$mailEvent): void {
            $event = $this->onMailBeforeSentEvent($event);

            if ($event instanceof MailBeforeSentEvent) {
                $mailEvent = $event;
            }
        };
        $this->addEventListener($this->eventDispatcher, MailBeforeSentEvent::class, $mailListener);

        $this->changeTransactionStateToPaid($orderId);

        $this->resetEventDispatcher();