/** TransactionService interface implementation. */
  @Override
  public void start() throws CantStartServiceException {

    /** I will initialize the handling of com.bitdubai.platform events. */
    EventListener eventListener;
    EventHandler eventHandler;

    eventListener =
        eventManager.getNewListener(
            EventType.INCOMING_CRYPTO_TRANSACTIONS_WAITING_TRANSFERENCE_EXTRA_USER);
    eventHandler = new IncomingCryptoTransactionsWaitingTransferenceExtraUserEventHandler(this);
    eventListener.setEventHandler(eventHandler);
    eventManager.addListener(eventListener);
    listenersAdded.add(eventListener);

    this.serviceStatus = ServiceStatus.STARTED;
  }
  @Override
  public void stop() {

    /** I will remove all the event listeners registered with the event manager. */
    for (EventListener eventListener : listenersAdded) {
      eventManager.removeListener(eventListener);
    }

    listenersAdded.clear();
    this.serviceStatus = ServiceStatus.STOPPED;
  }