public boolean addProxyMessage(ProxyMessage message) {
        assert streamId.equals(message.getInlongStreamId());
        try {
            if (queueIsFull()) {
                LOGGER.warn("message queue is greater than {}, stop adding message, "
                        + "maybe proxy get stuck", maxQueueNumber);
                return false;
            }
            messageQueue.put(message);
            queueSize.addAndGet(message.getBody().length);
            return true;
        } catch (Exception ex) {
            LOGGER.error("exception caught", ex);
        }
        return false;
    }
Add proxy message to cache, proxy message should belong to the same stream id.
inlong-agent/agent-common/src/main/java/org/apache/inlong/agent/message/PackProxyMessage.java