presto-main/src/main/java/io/prestosql/eventlistener/EventListenerManager.java/EventListenerManager/addEventListenerFactory
class EventListenerManager:    public void addEventListenerFactory(EventListenerFactory eventListenerFactory)
    {
        requireNonNull(eventListenerFactory, "eventListenerFactory is null");

        if (eventListenerFactories.putIfAbsent(eventListenerFactory.getName(), eventListenerFactory) != null) {
            throw new IllegalArgumentException(format("Event listener '%s' is already registered", eventListenerFactory.getName()));
        }
    }