code: def compute_n_instances_needed(
      self,
      ready_cores_mcpu: int,
      regions: List[str],
      remaining_max_new_instances_per_autoscaler_loop: int,
  ):
      pool_stats = self.current_worker_version_stats
      n_live_instances = (
          pool_stats.n_instances_by_state["pending"]
          + pool_stats.n_instances_by_state["active"]
      )
      live_free_cores_mcpu = sum(
          pool_stats.live_free_cores_mcpu_by_region[region]
          for region in regions
      )
  
      instances_needed = (
          ready_cores_mcpu
          - live_free_cores_mcpu
          + (self.worker_cores * 1000)
          - 1
      ) // (self.worker_cores * 1000)
      instances_needed = min(
          instances_needed,
          self.max_live_instances - n_live_instances,
          self.max_instances - self.n_instances,
          # 20 queries/s; our GCE long-run quota
          300,
          remaining_max_new_instances_per_autoscaler_loop,
      )
      return max(0, instances_needed)
  
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 9 for calling the Pool obj's underlying member method code with example usage: obj.compute_n_instances_needed(ready_cores_mcpu, regions, remaining_max_new_instances_per_autoscaler_loop) and returns: max