code: def __str__(self):
      return f"pool {self.name}"
  
imports: import asyncio
  import logging
  import random
  from collections import defaultdict
  from typing import Dict, List, Optional, Tuple
  import prometheus_client
  import sortedcontainers
  from gear import Database
  from hailtop import aiotools
  from hailtop.utils import AsyncWorkerPool, Notice, WaitableSharedPool, periodically_call_with_dynamic_sleep, retry_long_running, run_if_changed, secret_alnum_string, time_msecs
  from ...batch_format_version import BatchFormatVersion
  from ...globals import INSTANCE_VERSION
  from ...inst_coll_config import PoolConfig
  from ...utils import ExceededSharesCounter, regions_bits_rep_to_regions
  from ..instance import Instance
  from ..job import mark_job_errored, schedule_job
  from ..resource_manager import CloudResourceManager
  from .base import InstanceCollection, InstanceCollectionManager
label_desc: Use image node_id 10 for calling the Pool obj's underlying member method code with example usage: obj.__str__() and returns: str, self