code: def get_cluster_state_ref(self):
      return self._cluster_state_ref
  
imports: import asyncio
  import itertools
  import logging
  import os
  import time
  from typing import Union, Dict, List, Optional, AsyncGenerator
  from ...None import oscar
  from ...core.entrypoints import init_extension_entrypoints
  from ...metrics import init_metrics
  from ...oscar.backends.ray.driver import RayActorDriver
  from ...oscar.backends.ray.utils import process_placement_to_address, node_placement_to_address, process_address_to_placement
  from ...oscar.backends.ray.pool import RayPoolState
  from ...oscar.backends.router import Router
  from ...oscar.errors import ReconstructWorkerError
  from ...resource import Resource
  from ...services.cluster.backends.base import register_cluster_backend, AbstractClusterBackend
  from ...services import NodeRole
  from ...services.task.execution.api import ExecutionConfig
  from ...session import _new_session, new_session, AbstractSession, ensure_isolation_created
  from ...utils import lazy_import, retry_callable
  from ..utils import load_config, get_third_party_modules_from_config
  from .service import start_supervisor, start_worker, stop_supervisor, stop_worker
  from .pool import create_supervisor_actor_pool, create_worker_actor_pool
label_desc: Use image node_id 2 for calling the RayClusterBackend obj's underlying member method code with example usage: obj.get_cluster_state_ref() and returns: self