@Override
    protected Message<?> doConvert(Object payload, Map<String, Object> headers, MessagePostProcessor postProcessor) {
        Message<?> message = super.doConvert(payload, headers, postProcessor);
        MessageBuilder<?> builder = MessageBuilder.fromMessage(message);
        builder.setHeaderIfAbsent(MessageHeaders.CONTENT_TYPE, MimeTypeUtils.TEXT_PLAIN);
        return builder.build();
    }
Same to {@link #sendOneWayOrderly(String, Message, String)}

@param destination formats: `topicName:tags`
@param payload the Object to use as payload
rocketmq-spring-boot/src/main/java/org/apache/rocketmq/spring/core/RocketMQTemplate.java