code: def _interval_check(self):
      while True:
          # Get system statistics
          if self._shutdown:
              break
  
          time.sleep(1)
  
          client_uris = list(self._heartbeat_pool.keys())
          for client_uri in client_uris:
              now = datetime.datetime.now().timestamp()
              if (
                  now - self._heartbeat_pool[client_uri]
                  > self._client_keep_alive_time
              ):
                  self._release_client_resources(client_uri)
                  del self._heartbeat_pool[client_uri]
  
imports: import datetime
  import logging
  import time
  import weakref
  from collections import Counter
  from threading import Thread
  from typing import Union
  import aim.ext.transport.proto.remote_router_pb2
label_desc: Use image node_id 5 for calling the RPCHeartbeatWatcher obj's underlying member method code with example usage: obj._interval_check() without return types