code: public Closeable onMySubmittedOrderEvent(final BiConsumer<BitfinexAccountSymbol, Collection<BitfinexSubmittedOrder>> listener) {
          submittedOrderConsumers.offer(listener);
          return () -> submittedOrderConsumers.remove(listener);
      }
docs: registers listener for user account related events - submitted order events
  @param listener of event
  @return hook of this listener