app/bundles/WebhookBundle/Event/WebhookBuilderEvent.php

<?php

namespace Mautic\WebhookBundle\Event;

use Symfony\Component\Process\Exception\InvalidArgumentException;
use Symfony\Contracts\EventDispatcher\Event;
use Symfony\Contracts\Translation\TranslatorInterface;

class WebhookBuilderEvent extends Event
{
    private array $events = [];

    public function __construct(
        private TranslatorInterface $translator
    ) {
    }

    /**
     * Add an event for the event list.
     *
     * @param string $key   - a unique identifier; it is recommended that it be namespaced i.e. lead.mytrigger
     * @param array  $event - can contain the following keys:
     *                      'label'       => (required) what to display in the list
     *                      'description' => (optional) short description of event
     */
    public function addEvent($key, array $event): void
    {
        if (array_key_exists($key, $this->events)) {
            throw new InvalidArgumentException("The key, '$key' is already used by another webhook event. Please use a different key.");
        }

        $event['label']       = $this->translator->trans($event['label']);
        $event['description'] = (isset($event['description'])) ? $this->translator->trans($event['description']) : '';

        $this->events[$key] = $event;
    }

    /**
     * Get webhook events.
     *
     * @return array
     */
    public function getEvents()
    {
        static $sorted = false;

        if (empty($sorted)) {
            uasort($this->events, fn ($a, $b): int => strnatcasecmp(
                $a['label'], $b['label']));
            $sorted = true;
        }

        return $this->events;
    }
}