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

interface TraceableEventDispatcherInterface implements

addSubscriber(

removeSubscriber(

class RegisterListenersPass implements

int|null getListenerPriority(string $eventName, callable $listener) Gets the listener priority

wasCalled()

array getCalledListeners() Gets the called listeners.

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

bool hasArgument(string $key) Has argument.