* Event aggregator service
* A service that manage events inside application.
export abstract class EventAggregatorService {
* Publish event aggregator service
* @param eventType eventType
* @param eventArgs event argument
abstract publish(eventType: any, eventArgs: any);
* Listens event aggregator service
* @param eventType eventType
* @returns an `Observable` that emit whenever event occurs.
abstract listen<T>(eventType: any): Observable<T>;