public function addListener(string $eventName, callable $listener, int $priority = 0): void;
/**
* @param string $eventName preferably the fully-qualified class name of the Event sub class
* @param callable $listener the object that is invoked when a matching event is dispatched
*
* @since 19.0.0
*/
public function removeListener(string $eventName, callable $listener): void;
/**
* @param string $eventName preferably the fully-qualified class name of the Event sub class to listen for
* @param string $className fully qualified class name (or ::class notation) of a \OCP\EventDispatcher\IEventListener that can be built by the DI container