@JvmOverloads fun trigger(event: String, args: Map<String, Any> = HashMap()): Deferred<List<Any?>>
Triggers the event by calling all its bound callbacks with args as parameters.
event - The name of the event to be triggered.
args - The payload of the event, to be passed to the callbacks.
Return
Returns a deferred result that will be completed when all of the callbacks
have finished processing the triggered event.