code: public EventBusHookListener start(Handler<AsyncResult<Void>> doneHandler) {
      eventBus.registerHandler(address, messageHandler, doneHandler);
      return this;
    }
docs: Starts the hook listener, registering a handler on the event bus.
  
  @param doneHandler An asynchronous handler to be called once the listener
  handler has been registered on the event bus.
  @return The hook listener.