code: def is_terminated(self, node_id: str) -> bool:
      instances = self.acs.describe_instances(instance_ids=[node_id])
      if instances is not None:
          assert len(instances) == 1
          instance = instances[0]
          return instance.get("Status") == "Stopped"
      cli_logger.error("Invalid node id: %s", node_id)
      return False
  
imports: import logging
  import random
  import threading
  import time
  from collections import defaultdict
  from typing import Any, Dict, List, Optional
  from ray.autoscaler._private.aliyun.config import PENDING, RUNNING, STOPPED, STOPPING, bootstrap_aliyun
  from ray.autoscaler._private.aliyun.utils import AcsClient
  from ray.autoscaler._private.cli_logger import cli_logger
  from ray.autoscaler._private.constants import BOTO_MAX_RETRIES
  from ray.autoscaler._private.log_timer import LogTimer
  from ray.autoscaler.node_provider import NodeProvider
  from ray.autoscaler.tags import TAG_RAY_CLUSTER_NAME, TAG_RAY_LAUNCH_CONFIG, TAG_RAY_NODE_KIND, TAG_RAY_NODE_NAME, TAG_RAY_NODE_STATUS, TAG_RAY_USER_NODE_TYPE
label_desc: Use image node_id 4 for calling the AliyunNodeProvider obj's underlying member method code with example usage: obj.is_terminated(node_id) and returns: False, unknown