return super.writeReplace();
            }
          };
      return new CartesianSet<E>(axes, new CartesianList<E>(listAxes));
    }

    private CartesianSet(ImmutableList<ImmutableSet<E>> axes, CartesianList<E> delegate) {
      this.axes = axes;
      this.delegate = delegate;
    }

    @Override
    protected Collection<List<E>> delegate() {

    `Cache.urls()` would prevent in-flight entries from being written.


## Version 3.14.3

_2019-09-10_

 *  Fix: Don't lose HTTP/2 flow control bytes when incoming data races with a stream close. If this
    happened enough then eventually the connection would stall.

 *  Fix: Acknowledge and apply inbound HTTP/2 settings atomically. Previously we had a race where we

streaming_async                   (on|off)    set to 'on', to enable asynchronous publish
streaming_max_pub_acks_in_flight  (number)    number of messages to publish without waiting for ACKs
streaming_cluster_id              (string)    unique ID for NATS streaming cluster
cert_authority                    (string)    path to certificate chain of the target NATS server

   * listeners for future n may complete before some for future n-1.) However, it is possible, if
   * one input completes with result X and another later with result Y, for Y to come before X in
   * the output future list. (Such races are impossible to solve without global synchronization of
   * all future completions. And they should have little practical impact.)
   *