removeListener method
Removes the given event listener. @param event The event for which to remove a listener. @param listener The listener to remove. @returns A reference to the event emitter such that calls can be chained.
Implementation
AsyncEventEmitter removeListener(String event, Handler<dynamic> listener) {
final listeners = _getListeners(event);
final index = listeners.indexOf(listener);
if (index != -1) {
listeners.splice(index, 1);
}
return this;
}