@Override
        public String toString() {
            return String.format("default %d finished %d delete %d other %d", defaultCount, finishedCount,
                    deleteCount, otherCount);
        }
handle the instance created by task, including add, delete, update etc.
the instance info is saved in both store and memory.
inlong-agent/agent-core/src/main/java/org/apache/inlong/agent/core/instance/InstanceManager.java