code: @Override
      public Stream<T> queued(int queueSize) {
          final Iterator<T> iter = iterator();
  
          if (iter instanceof QueuedIterator && ((QueuedIterator<? extends T>) iter).max() >= queueSize) {
              return newStream(elements, sorted, cmp);
          } else {
              return newStream(Stream.parallelConcatt(Arrays.asList(iter), 1, queueSize), sorted, cmp);
          }
      }
docs: Returns a Stream with elements from a temporary queue which is filled by reading the elements from the specified iterator asynchronously.
  
  @param stream
  @param queueSize Default value is 8
  @return