The Joomla/Symfony Event Dispatcher Bridge package bridges the joomla/event and symfony/event-dispatcher packages, allowing the Joomla API to be used within the Symfony API.
Add "joomla/symfony-event-dispatcher-bridge": "~2.0@dev" to the require block in your composer.json and then run composer install.
{
"require": {
"joomla/symfony-event-dispatcher-bridge": "~2.0@dev"
}
}Alternatively, you can simply run the following from the command line:
composer require joomla/symfony-event-dispatcher-bridge "~2.0@dev"