Set as second argument a emitter instance, otherwise the factory creates a new one.
Event array could have a name-handler-pair, a listener provider as instance of
\League\Event\ListenerProviderInterface or a argument array with name, handler and priority
Configure event array as follows:
$events = [
name-handler-pair
'eventName' => function()},
listener provider as instance of \League\Event\ListenerProviderInterface
new \Acme\MyListenerProvider
argument array name, handler, prio
['name', function()}, 10]
alternating argument array name => [handler, prio]
'eventName' => [function()}, 10]
];