code: private void sequenceCommand(long sequence, ServerSessionContext session, CompletableFuture<Result> future, ThreadContext context) {
      if (!log.isOpen()) {
        context.executor().execute(() -> future.completeExceptionally(new IllegalStateException("log closed")));
        return;
      }
  
      Result result = session.getResult(sequence);
      if (result == null) {
        LOGGER.debug("Missing command result for {}:{}", session.id(), sequence);
      }
      context.executor().execute(() -> future.complete(result));
    }
docs: Sequences a command according to the command sequence number.