public static SchedulisStructureStandard getInstance(){
        if(instance == null){
            synchronized (SchedulisStructureStandard.class){
                if (instance == null){
                    instance = new SchedulisStructureStandard();
                }
            }
        }
        return instance;
    }
Schedulis's engineering integration specification is a singleton.
dss-appconn/appconns/dss-schedulis-appconn/src/main/java/com/webank/wedatasphere/dss/appconn/schedulis/standard/SchedulisStructureStandard.java