code: public static <E1> ConcurrentConveyor<E1> concurrentConveyor(
              E1 submitterGoneItem, QueuedPipe<E1>... queues
      ) {
          return new ConcurrentConveyor<E1>(submitterGoneItem, queues);
      }
docs: Creates a new concurrent conveyor.
  
  @param submitterGoneItem the object that a submitter thread can use to
  signal it's done submitting
  @param queues            the concurrent queues the conveyor will manage