class_docstr: Extend Dask's Worker with routes to handle PubSub machinery
code: def remove_subscriber(self, name=None, address=None):
      for pub in self.publishers[name]:
          del pub.subscribers[address]
  
imports: from __future__ import annotations
  import asyncio
  import logging
  import threading
  import weakref
  from collections import defaultdict, deque
  from dask.utils import parse_timedelta
  from distributed.core import CommClosedError
  from distributed.metrics import time
  from distributed.protocol.serialize import to_serialize
  from distributed.utils import TimeoutError, sync, wait_for
label_desc: Use image node_id 3 for calling the PubSubWorkerExtension obj's underlying member method code with example usage: obj.remove_subscriber(name, address) without return types