bool hasListeners(string $eventName = null) Checks whether an event has any registered listeners

removeSubscriber(

addSubscriberService(string $serviceId, string $class) Adds a service as event subscriber.

class ImmutableEventDispatcher implements

addListener(string $eventName, callable $listener, int $priority) Adds an event listener that listens

removeListener(string $eventName, callable $listener) Removes an event listener from the specified

stopPropagation() Stops the propagation of the event to further event listeners. If multiple

array getListeners(string $eventName = null) Gets the listeners of a specific event or all listeners

addListenerService(string $eventName, array $callback, int $priority) Adds a service as event listener

class EventDispatcher implements