Method init

tutorial/MyGNode/MyPubMessageNode.h:17–23

class MyPubMessageNode : public CGraph::GNode {
public:
    CStatus init() override {
        int sleep = 300;
        CGRAPH_SLEEP_MILLISECOND(sleep)    // 休息，确保其他的sub节点，已经完成了订阅
        CGraph::CGRAPH_ECHO("==> [MyPubMessageNode] [init], sleep [%d] ms, to make sure sub node prepare ok.",
                            sleep);
        return CStatus();
    }

    CStatus run() override {
        std::shared_ptr<MyMessageParam> mp(new MyMessageParam());    // 创建一个消息，并且发送出去