/**
   * Handles a publish request.
   *
   * @param request The publish request to handle.
   * @return A completable future to be completed with the publish response.
   */
  @SuppressWarnings("unchecked")
  private CompletableFuture<PublishResponse> handlePublish(PublishRequest request) {
    if (request.session() != id)
      return Futures.exceptionalFuture(new UnknownSessionException("incorrect session ID"));

    if (request.previousVersion() != eventVersion) {
      return CompletableFuture.completedFuture(
          PublishResponse.builder()
              .withStatus(Response.Status.ERROR)
              .withError(RaftError.Type.INTERNAL_ERROR)
              .withVersion(eventVersion)
              .build());
    }

    eventVersion = request.eventVersion();

    List<CompletableFuture<Void>> futures = new ArrayList<>(request.events().size());
    for (Event<?> event : request.events()) {
      Listeners<Object> listeners = eventListeners.get(event.name());
      if (listeners != null) {
        futures.add(listeners.accept(event.message()));
      }
    }

    return CompletableFuture.allOf(futures.toArray(new CompletableFuture<?>[futures.size()]))
        .handleAsync(
            (result, error) -> {
              completeVersion = Math.max(completeVersion, request.eventVersion());
              return PublishResponse.builder()
                  .withStatus(Response.Status.OK)
                  .withVersion(eventVersion)
                  .build();
            },
            context.executor());
  }
 @Override
 public Session publish(String event, Object message) {
   Assert.notNull(event, "event");
   context
       .executor()
       .execute(
           () -> {
             Listeners<Object> listeners = eventListeners.get(event);
             if (listeners != null) {
               listeners.accept(message);
             }
           });
   return this;
 }