标签：MQClientAPIImpl,发送,源码,消息,context,sendResult,null From： https://www.cnblogs.com/wjweily/p/17788945.html
SendResult sendResult = MQClientAPIImpl.this.processSendResponse(brokerName, msg, response);
if (context != null && sendResult != null) {
context.setSendResult(sendResult);
context.getProducer().executeSendMessageHookAfter(context);
}