code: def remove_instance(self, instance: Instance):
      self.n_instances_by_state[instance.state] -= 1
      self.cores_mcpu_by_state[instance.state] -= instance.cores_mcpu
  
      if instance.state in live_instance_states:
          self.live_free_cores_mcpu_by_region[
              instance.region
          ] -= instance.free_cores_mcpu_nonnegative
  
      if instance.state == "active":
          self.active_schedulable_free_cores_mcpu -= (
              instance.free_cores_mcpu_nonnegative
          )
  
imports: import asyncio
  import collections
  import logging
  import re
  import secrets
  from typing import Any, Counter, Dict, List, Optional, Tuple
  import sortedcontainers
  from gear import Database
  from gear.time_limited_max_size_cache import TimeLimitedMaxSizeCache
  from hailtop import aiotools
  from hailtop.utils import periodically_call, secret_alnum_string, time_msecs
  from ...globals import INSTANCE_VERSION, live_instance_states
  from ...instance_config import QuantifiedResource
  from ..instance import Instance
  from ..location import CloudLocationMonitor
  from ..resource_manager import CloudResourceManager, UnknownVMState, VMDoesNotExist, VMStateCreating, VMStateRunning, VMStateTerminated
label_desc: Use image node_id 2 for calling the InstanceCollectionStats obj's underlying member method code with example usage: obj.remove_instance(instance) without return types