.delayElements(Duration.ofMillis(ThreadLocalRandom.current().nextLong(500, 1500)))
.map(i -> "Message #" + i)
.flatMap(message -> sendMessage(chatRoom, message)
.delayElements(Duration.ofMillis(ThreadLocalRandom.current().nextLong(500, 1500)))
.map(i -> "Message #" + i)
.flatMap(message -> sendMessage(chatRoom, message)