class_docstr: Provide python APIs for job submission and management.
  
  It does not provide persistence, all info will be lost if the cluster
  goes down.
code: def _get_actor_for_job(self, job_id: str) -> Optional[ActorHandle]:
      try:
          return ray.get_actor(
              JOB_ACTOR_NAME_TEMPLATE.format(job_id=job_id),
              namespace=SUPERVISOR_ACTOR_RAY_NAMESPACE,
          )
      except (
          ValueError
      ):  # Ray returns ValueError for nonexistent actor.
          return None
  
imports: import asyncio
  import copy
  import json
  import logging
  import os
  import psutil
  import random
  import signal
  import string
  import subprocess
  import sys
  import time
  import traceback
  from asyncio.tasks import FIRST_COMPLETED
  from collections import deque
  from typing import Any, Dict, Iterator, List, Optional, Tuple, Union
  from ray.util.scheduling_strategies import NodeAffinitySchedulingStrategy, SchedulingStrategyT
  import ray
  from ray._private.gcs_utils import GcsAioClient
  from ray._private.utils import run_background_task
  import ray._private.ray_constants
  from ray._private.runtime_env.constants import RAY_JOB_CONFIG_JSON_ENV_VAR
  from ray.actor import ActorHandle
  from ray.dashboard.consts import RAY_JOB_ALLOW_DRIVER_ON_WORKER_NODES_ENV_VAR, DEFAULT_JOB_START_TIMEOUT_SECONDS, RAY_JOB_START_TIMEOUT_SECONDS_ENV_VAR
  from ray.dashboard.modules.job.common import JOB_ID_METADATA_KEY, JOB_NAME_METADATA_KEY, JOB_ACTOR_NAME_TEMPLATE, JOB_LOGS_PATH_TEMPLATE, SUPERVISOR_ACTOR_RAY_NAMESPACE, JobInfo, JobInfoStorageClient
  from ray.dashboard.modules.job.utils import file_tail_iterator
  from ray.exceptions import ActorUnschedulableError, RuntimeEnvSetupError
  from ray.job_submission import JobStatus
  from ray._private.event.event_logger import get_event_logger
  from ray.core.generated.event_pb2 import Event
label_desc: Use image node_id 2 for calling the JobManager obj's underlying member method code with example usage: obj._get_actor_for_job(job_id) and returns: ray, None